RPM Test; a tale of three twists, Chapter 2

[leftiye]

So, when you add ten grains of powder to an accurate load, and fire it in a too tight twist does it stabilize at all, or just fly off into never never wherever? Did it lose accuracy, or did it not ever have it to lose. There's your straight question Larry, let's see if you can stay on subject.

[leftiye]

So now it's everybody'd RPM theory. Isn't that convenient!

[BABore]

I would like to see the same test using bullets lubed with LBT Blue. I can guarrantee you that if I changed to 50/50 Alox-beeswax lube on one of my accurate HV loads, it would shoot all over the place. Drop the velocity and that can easily change things. This I know cause I have done it. Even more or less similar lubes can change the result drastically when shot side-by side. It seems like your purposely throwing a monkey wrench in the mix when you just simply add more powder and expect to prove something. It just don't work like that.

[Larry Gibson]

Leftiye

About time you got around to asking a straight question.

Yes the bullet was stable. That was well documented through out the Chapter 2 test. The measured BCs demonstrated this. Were the bullet not stable the BCs would have not been as consistent as they were with all three barrels. The 10" twist with this load faired no worse than the other two twists. While the accuracy was not good the "10 gr more load" exhibited exactly what Bass said it would if RPM was the culprit when he proposed this last test. That was that the bullet would lose accuracy in a larger non-linear fashion. That is exactly what happened with this test of the 38 gr load.

Since a 171 gr bullet is in the middle of the stability spectrum for a 10” twist barrel at 2500 fps I’d not say that it was not stabilized at all or that it never had stability. The reasons for this are there was no leading in the bore to indicate stripping and the bullet holes are nice and round all the way to 200 yards. Nothing there to indicate the bullet was unstable. Obviously from the accuracy of the 28 gr load the bullet had the accuracy capability. Thus it is my contention that something was affecting it’s accuracy during flight. That something is RPM.

Now if we look at the 28 gr load we see that it's RPM is still within the RPM threshold and it has not yet reached the point where the RPM are overcoming the rotational stability. Thus it's accuracy is linear throughout the test. The 38 gr load is well above the RPM threshold and it is obvious the RPM is adversely effecting it's accuracy in a very non-linear way.

We have discussed previously that the bullet may still be stable yet is cork screwing around its flight path. Apparently that is what is occurring. More testing would be required to confirm that. The bullet at some point down range may actually become unstable and fly off into “never never where ever”. Perhaps this is what’s happening to Bass’s bullets(?). I’ve never actually shot a load that was shooting this badly at 200 yards any farther away so I can’t say. I have seen other bullets go awry the same way though so I suspect instability at some point down range is the reason in this case also.

Yes it is “everyone’s PM theory”. The facts are simply there. Drive a regular cast bullet above it’s RPM threshold (that threshold is in the 125-140,000 RPM range for most cast bullets) and inaccuracy in a non-linear fashion is the result. As to it’s “convenience”, I’d say it is damn well pretty inconvenient! I would much prefer to drive this 311291 at 2500 fps with 2 moa accuracy out of any .308 or ’06 all the way to 500/600 yards. It just isn’t going to happen is all. RPM is the reason why.

Larry Gibson

BTW; you will probably come back with "more oatmeal" etc, ad nauseum saying I've avoided your question. I actually expect that. However, I have answered your question(s) and everyone will see that. If you don't like the answer that is fine. Kindly say why and give some sort of facts to back up your disagreement. Otherwise everyone will see your response for what it is.

[Larry Gibson]

I would like to see the same test using bullets lubed with LBT Blue. I can guarrantee you that if I changed to 50/50 Alox-beeswax lube on one of my accurate HV loads, it would shoot all over the place. Drop the velocity and that can easily change things. This I know cause I have done it. Even more or less similar lubes can change the result drastically when shot side-by side. It seems like your purposely throwing a monkey wrench in the mix when you just simply add more powder and expect to prove something. It just don't work like that.

BaBore

10" twist .308s are rather common as are 311291 moulds. Why don't you just conduct the test yourself?

However, I will be testing the effects of different lubes later on in the RPM test I am conducting (doesn't anyone read what I post or are some just jumpimg to erronious assumptions?). FYI; I have used LBT Blue in the past and found no difference in accuracy with regular cast bullets compaired to Javelina up through 2600 fps. So I actually already have performed your test although it was with an '06 and 311291 and 311299.

In the continuing RPM test I will be testing Lar's lubes including his Carnuba Red, BAC and 2500+. If you want to send me a tube of LBT Blue I'll try that too. PM me for the address.

Larry Gibson

[leftiye]

[We have discussed previously that the bullet may still be stable yet is cork screwing around its flight path. Apparently that is what is occurring. More testing would be required to confirm that. The bullet at some point down range may actually become unstable and fly off into “never never where ever”. Perhaps this is what’s happening to Bass’s bullets(?). I’ve never actually shot a load that was shooting this badly at 200 yards any farther away so I can’t say. I have seen other bullets go awry the same way though so I suspect instability at some point down range is the reason in this case also.] Larry gibson.

Larry, Have you yet figured out how a boolit flying point-on could fly in a spiral ?

This which is quoted above is exactly what I had in mind when I postulated a boolit being unstable from the beginning of it's flight. It may be semantics, but I don't see corkscrewing as being stable (kinda violates the defintion, doesn't it?). Plus, while Ballistic Coefficient might detect cork screwing (though cork screwing might have to be quite substantial before the time of flight was changed enough to pick up), it wouldn't detect simple inaccuracy as the boolit that is truely stable (not corkscrewing) only travels about .001," (maybe less) farther at 100 yds. to make a 4 or 5 inch group (or much bigger) than would one printing a perfect one hole group (trigonometry - with two legs of a right triangle 100 yds. in length, one diverging from the right angle at that distance by 2"). Do you have any idea how much farther a boolit would have to travel before it would show up in the B.C.? Might be quite a ways at 2500 fps.

It would seem to be necessary in any theory that the earlier flight of a given round would exhibit unstability if the later flight were supposed to get worse. However, both Bass's theory and yours do show ways for a stable boolit to become unstable. As always, the question is, "how did it get unstable?" Supporting issues are those that exacerbate the instability (again, by definition - if something makes a pre-existing condition worse it isn't the primary factor. ).

[Larry Gibson]

Leftiye

Larry, Have you yet figured out how a boolit flying point-on could fly in a spiral ?

Hard to describe but if the center of gravity does not coincide with the center of form (this is true of most bullets in flight, again it is why we shoot groups instead of one hole) as the bullet spins the centrifugal force causes the bullet to corkscrew or rotate around it's axis of flight. It appears that this is what begins to happen when the bullet excedes it's RPM threshold. It also appear that the bullet is able to fly point on for a distance then it becomes unstable somewhere out there. Further testing could prove or disprove this line of thinking. I may get to it down the road.

This which is quoted above is exactly what I had in mind when I postulated a boolit being unstable from the beginning of it's flight. It may be semantics, but I don't see corkscrewing as being stable (kinda violates the defintion, doesn't it?). Plus, while Ballistic Coefficient might detect cork screwing (though cork screwing might have to be quite substantial before the time of flight was changed enough to pick up), it wouldn't detect simple inaccuracy as the boolit that is truely stable (not corkscrewing) only travels about .001," (maybe less) farther to make a 4 or 5 inch group than would one printing a perfect one hole group (trigonometry - with two legs of a right triangle 100 yds. in length, one diverging from the right angle at that distance by 2"). Do you have any idea how much farther a boolit would have to travel before it would show up in the B.C.? Might be quite a ways at 2500 fps.

Yes it is obviously a matter of semantics. I think of a bullet being "unstable" when it either hasn't enough RPM to achieve stability or wobble, yaw and pitch are excessive. In the case at hand we know that the bullet does have enough RPM to be rotationally stable. We also know by the consitent BCs that wobble, pitch and yaw are not excessive. Something else is happening. The tests are showing that RPM, at a certain point, has a very detrimental effect on a regular cast bullets accuracy. What exactly is that effect and how it works are what we are learning.

Perhaps you are right and this cork screwing effect is not "stable" in the larger text of the definition. Still it seems the bullets are flying point on to a certain point. I further think that as the corkscrew gets larger and larger the bullet does get unstable with wobble, yaw and pitching happening to the degree that the bullet sails off into never never where ever as Bass describes. Bass figured it was between 200 and 400 yards that it was happening. I don't doubt that based on the 14.5" group I was getting at 200 yards I'd guess the 311291s I was shooting at 2500 fps would be unstable very shortly after that. Perhaps they already were going unstable at 200 yards (?). The LBT bullet bass uses is much better designed for HV so I would expect it to go further before it went unstable. It appears that assumption is correct.


It would seem to be necessary in any theory that the earlier flight of a given round would exhibit unstability if the later flight were supposed to get worse. However, both Bass's theory and yours do show ways for this to possibly come to pass. As always, the question is, "how did it get unstable?" Supporting issues are those that exacerbated the instability (again, by definition).

Again we agree. Unstable is a condition of flight. The bullets may be imbalanced in the barrel but they are stable as they are restrained by the barrel. When in flight they are then unrestrained. In order for the imbalanced bullet to become unstable (given a sufficient twist for stability which we have here) something must act upon those imbalances. It is the effects of the centrifugal force caused by RPM that acts upon them. At some point the centrifugal force over comes the rotational stability. This is the area I refer to as the RPM threshold. Before that point the rotational stability of the cast bullet keeps it accurate. It was very obvious that this happens early in the bullets flight as exhibited by the 2.5" 50 yard group of the HV load. As the range increased so did the adverse effect in a very non-linear manner. Again I think we are in agreement here.

Larry Gibson

[Tiger]

I would like to see the same test using bullets lubed with LBT Blue. I can guarrantee you that if I changed to 50/50 Alox-beeswax lube on one of my accurate HV loads, it would shoot all over the place. Drop the velocity and that can easily change things. This I know cause I have done it. Even more or less similar lubes can change the result drastically when shot side-by side. It seems like your purposely throwing a monkey wrench in the mix when you just simply add more powder and expect to prove something. It just don't work like that.

I feel like super delegate when I say I endorse what BABore has to say.
Larry aside from the bullet lube is one most important things in shooting cast bullets. Before you go off I am not making accusations just saying what you already say...try different lubes beside the good 50/50 you have been using. Myself I never tried HV loads with 50/50 to start with.

Ralf

[leftiye]

How about we go with the (I think) standard definition - stable is rotating around the boolit's axis, no wobble. Any wobble, however typified is a degree of instability. It's not required to be in flight, it could be spinning stably on it's nose (or wobbling). It's about the boolit, not about flight. And if it becomes unstable the moment it becomes free of the barrel, it isn't rpms, it's either a deformed boolit or a bad launch. Rpm hasn't had time to do anything yet.

And once it becomes unstable, air resistnce can act upon the boolit to further unstabilize it.

You just can't assume that the B.C.s are ruling out a yawing or other minor instabilities. Nor can you say that it precludes deformations of the boolits. We all know these deformations are happening. It's one of the facts of reality. I've been at this since you first posted your test (I WILL add - with no answer from you). Things like this that threaten to unravel your whole test cannot be let go by, nor be ignored if you want in the end to claim a valid test.

[Larry Gibson]

Ralf

It's been in the plan from the beginning.

Larry Gibson

[Larry Gibson]

Leftiye

How about we go with the (I think) standard definition - stable is rotating around the boolit's axis, no wobble. Any wobble, however typified is a degree of instability. It's not required to be in flight, it could be spinning stably on it's nose. And if it becomes unstable the moment it becomes free of the barrel, it isn't rpms, it's either a deformed boolit or a bad launch. Rpm hasn't had time to do anything yet.

I can live with that definition.

Don't understand the nose part?

Instability can be caused by other things, i.e. a bad crown, etc. However, if the bullet exhibits the same BC as another same bullet fired out of a slower twist then the stability is the same. That the slower twist gives proportionall better accuracy at HV is telling us it is not because the faster twist bullets are damaged more or launched badly.

The effects of RPM on the HV bullet began very close to the muzzle as evidenced by the 50 yard group size and the continued larger size of the groups at 100 and 200 yards. It is a cumulative effect which is why the groups open at a non-linear rate.

Now I did admit to 3 "bad launches" in that test and called them. The rest were all good launches. Note the group sizes of the 28 gr load; a 2.5" 9 shot group at 200 yards ain't to shabby for a sporter rifle shooting cast bullets.

And once it becomes unstable, air resistnce can act upon the boolit to further unstabilize it.

Quite correct but that is if we have a really unstable bullet. We have no evidence of that as the computed BCs at 100 yards show.

You just can't assume that the B.C.s are ruling out a yawing or other minor instabilities. Nor can you say that it precludes deformations of the boolits. We all know these deformations are happening. It's one of the facts of reality. I've been at this since you first posted your test (I WILL add - with no answer from you). Things like this that threaten to unravel your whole test cannot be let go by, nor be ignored if you want in the end to claim a valid test.

Well, I'll tell you what I told you at the beginning since you were there. Yes we can assume that BCs tell us of yawing or other minor instabilities. Yawing, pitching and wobble along with all the other instabilities adversely effect the flight. They do that by causing the bullet to not fly as efficiently through the air. The efficiency of the bullet to fly through the air is measured by time of flight lost over a measured distance and compared to a "standard model". I measured the time of flight and the M43 computed the BC based on a G1 model. It is a measurement to the third decimal. Small variations can and are noted. We can see when the BC goes south so does the accuracy. The problem here is the BCs didn't go south but the accuracy did. The accuracy went south to a much greater proportional degree with the faster twist. The BCs remained the same between the twists when that accuracy went south. That tells us the stability of the bullets was the same and something else was causing the inaccuracy. Quite simple actually.

Another thing to remember is that the BCs of FN and RN bullets will decrease (most often) as velocity is increased. In the case here the BCs decreased at the same rate with each twist. Yet the accuracy decreased to a much greater proportional degree with the faster twists. That does not "threaten to unravel your whole test". Quite the contrary; it substantiates the test and the evidence that RPM is the culprit. I have not ignored it at all. The BCs are graphed out and studied in comparison with the other data.

The simple fact is; given two like bullets at the same velocity with one being more stable than the other, the more stable bullet is more efficient in flight. It will arive at the target quicker with less velocity loss. The more stable bullet will have a higher BC. The less stable bullet with have a lower BC. It is measureable and I measure them.

Exactly how do you measure BCs? Can you tell me it can't be done based on your experience?

I would like answers to the above two questions please.

Larry Gibson

[leftiye]

Larry, a fine treatise on practical Ballistic Coefficients.

No one said that B.C.s couldn't be measured. What I said was that given the propensity of boolits to cover distances quickly, even your quartz clock in your computer can't differentiate the differences in time between a perfect boolit flying at the axis of the line of fire from one with minor to maybe moderate deviations. You're right, the deviating boolit will at some point show up in decreased B.C.s, but at what amount of elapsed time will the computer and the program actually register a difference. And how much farther will the boolit have to travel in order to accomplish this?

As I pointed out a stable boolit would be clear off of your screens in POI before it traveled more than a thousandth or two of an inch longer distance than the one which impacted the center of the target. Your machine probly cannot measure the TOF at 2500 fps to travel .002"? Again, How much wobble, yaw, corkscrewing, or just screwing around does a boolit have to do before TOF becomes stretched out enough to affect your machine's B.C. calculations? It isn't even that black and white. How much longer TOF is necessary before it changes something with that program (B.C. number to the third place)?

As for the two questions you asked - so you can't say I'm not answering your questions. I don't measure B.C.s. And it's got nothing to do with my experience. We're talking about YOUR machine here. The distance that a boolit will travel can be calculated from the velocity and the minimum unit of time your machine will calculate. Then one can calculate how much of a spiral would have to be flown to add that much TOF to a given boolits flight. That would give you the minimum deflection (other than straight line) that will show up in your calculations. Perhaps easier, and more accurate still, take the minimum time change that will affect the B.C. as per your program, and calculate from that.

No, You CAN'T assume stable boolits, and no deformations because of B.C.s not showing a variance. You maybe correct in your assumption, but as you've said (I think) "Assumptions don't cut it." Not even yours.

[runfiverun]

note larrys 2.5" 200 yd group would be dead linear with the results i have had so far.
at 50 and 100 yds,
i will get the 200 yd group shot hopefully this week.
bass's prediction of the hv group going bad somewhere after 200 [never,never land]
is exactly tthe results i got when shot at 300 notice i only found 4 shots on a 4'x4' board.
i would think that this qualifies as neverland.

where do i get this LBT blue at maybe i will try the 37gr load again?
think i will need a boolit harder then4/6 mix? should i water drop some?

and i think larry needs a nap........lol

[Larry Gibson]

runfiverun

You got that right! A drink too!

Larry Gibson

[Larry Gibson]

Leftiye

So ok, let’s talk about “my Machine”, a M43. What is it do you know about it? Do you know haw fast it measures and how it computes BCs? How long have you been designing and or engineering chronographs and computers? Please tell us how you can be so emphatic that the M43 can’t measure BCs quick enough?

You are wrong in your opinion and assumption on the capability of the m43 to accurately measure subtle changes in BCs. Again remember the BC is derived from a loss of velocity over a specified distance. This is then compared to a “standard model”.

Below is the result of a 10 shot string of m118 fired in this rifle. I’ll list the velocity, the remaining velocity (284 ft), fps loss and the BC.

2661/2473/188/.476
2664/2475/189/.475
2641/2458/183/.487
2648/2459/189/.474
2656/2474/182/.494
2677/2489/188/.478
2673/2485/188/.479
2646/2462/184/.486
2661/2472/189/.474
2676/2491/185/.487

The 10 shot string had a muzzle velocity of 2630 fps with an ES of 36 fps. The ES of the BC (average .481) was .020. The velocity loss ES of the 10 shots was only 7 fps with an average of 185. So for every 1 fps difference in velocity loss there was a .0033 change in the BC. The group size was 1.925”.

Conversely a 10 shot string with the same M118 ammunition out of the 12” twist gave an average BC of .517 with an ES of .016, a muzzle velocity of 2644 fps with an ES at the muzzle of 42 fps, an ES for the velocity loss of 6 fps with an average of 172 fps loss. For every 1 fps difference in velocity loss there was a .002666 change in BC. The group size was 1.025”.

In both cases the computer rounds up the BC to the third decimal point as that is "industry" standard and just plain keeps it manageable. As it was aptly put but the designer and builder, Dr. Oehler; "the third decimal point on the BC is equivelent to asking; is the deer 191 or 192 yards away?". However, the third decimal is there and it certainly gives us an incite into subtle changes in a bullets flight.

That’s pretty close measurement to me but then I don’t have a PHD in mathematics, do you?

But let’s be practical and look at it this way; same ammo out of two rifles, one with a 10” twist and one with a 12” twist. The 10” twist gives a BC of .481 and the 12” twist a BC of .517. The 10” twist shoots a 10 shot group of 1.925”. The 12” twist shoots a 10 shot group of 1.025”. The worst BC also has the largest group. The group with the Best BC (largest) also has the smallest group. The smaller (worse) BC tells us that the bullets out of the 10” twist are not as stable as the same bullets out of the 12” twist barrel and should not be as accurate. Lo and behold, they are not! Amazing how that works.

Larry Gibson

(now I really do need that drink!)

[Larry Gibson]

Leftiye

Like I said I'm not a PHD in math but I think you need to double check your math. If the radii of the corkscrewing bullet is 2" from the axis of flight at 100 yards then that is the divergence at that range. A .001" divergence of a 10" twist (the divergence of a cork screwing bullet is around the axis of flight) and if it diverges .001" per revolution it is only .36" at 100 yards. Anyone who is familiar with calculating sight adjustment of iron sights can tell you that. That is hardly "off the screens" as you put it.

Perhaps I'm not understanding what your math problem is supposed to represent? The bullets actually diverge 1.25" (from center of group) at 50 yards, 2.35" at 100 yards and 7.75" at 200 yards. That divergence is evidenced by holes in the paper, not abstract theory. Whether or not they were cork screwing I can not say for sure. That remains to seen by testing. One thing for sure though, those bullets were stable at least at 100 yards with a very non-linear divergence.

Larry Gibson

[leftiye]

Yep, you don't understand. Nobody is hammering your machine, I'd love to have one like it. I'm not saying it is inadequate at all.

Maybe let's look at your data about es. of B.C.s How far can one of those boolits fly in the elapsed time differences between those B.C.s?

I'll go back to my illustration of stable boolits (completely stable, not corkscrewing) that are perfectly accurate that for some reason make a 10 " group at 100 yards (and for purpses of argument we will lie and say that they're still going through your chrono screens). What is the time of flight differential for the ones 5" off the orange patch versus the one in the center of the targ dot? If you do a trigonometric (I'd have to look it up to be able to do it) calculation of those that are 5" to the right versus the one in the center, you would probly find it has only traveled a few thousandths of an inch farther than the one in the center did. Not knocking your machine, but how long does it take that boolit to travel a couple of thousandths of an inch? Most certainly they will give identical B.C.s, and let's put it this way - virtually nothing could read the difference in their elapsed time (it's about twelve mllionths of a second, probly way less). Yet they're all over h@!! accuracy wise!

Nothing will register a change in B.C. until the difference in elapsed time exceeds the smallest time that makes a difference to your computer. How far can a boolit travel in that time? You have to answer what the smallest increment of time that your machine can read is, MORE importantly what is the smallest unit of time your program is prepared to notice (reads makes a diff. in B.C.)? Then we can compute how far a boolit can travel at 2500 fps. in that time span. Then we can (with some help) calculate how big of a spiral would be necessary to divert the boolit that far. Then we will know how much (cork)screwing around a boolit can do before your machine notices it.

Then we will have a picture of just how stable those boolits are or aren't. More correctly we'll know how unstable they can be before we know anything about it.

[Larry Gibson]

Leftiye

Me thinks you spend too much time at a keyboard instead of behind a rifle. You took a broad swipe at the "machine; "even your quartz clock in your computer can't differentiate the differences in time between a perfect boolit flying at the axis of the line of fire from one with minor to maybe moderate deviations."

"Nothing will register a change in B.C. until the difference in elapsed time exceeds the smallest time that makes a difference to your computer." Just how is it you know this for a fact? My guess is you don't because the M43 is quite capable of making those measurements. This is just another assumption on your part in a vain attempt to stave off admitting you are wrong. Unless you can come up with some documented evidence showing the M43 is incapable your reasoning is flawed from the get go.

You are wrong and you are confused. The M43 can and does do it. I gave you ample proof of that. Now you too want to renege and say oh hey golly gee I wasn't hammering your machine....like hell you weren't. I've given you the velocity lost figure for each round. That is the the measurement of time of flight. The more velocity lost the longer it took the bullet to get there. That answers your question on how long it takes the bullet to get there. Coincidently the more velocity lost the lower the BC. The M43 measures the time of flight in microseconds. Since you're not bragging up your PHD in mathamatics I guess you don't know what "microseconds are". You might try a Google search and find out.

How you equate .001" to be 5" at 100 yards still mystifies me (and I'll bet anyone else reading this) . Just what the heck are you trying to say? Perfectly stable bullets that are perfectly accurate do not give 10" groups. The point we're looking at is that Inaccurate bullets can fave rotational stability. Rotational stability simply means they are flying point on. It does not mean they do not have any yaw, pitch or wobble. All bullets one or a combination of them during flight. Rotaional stability does not mean the bullet is accurate. It only means the bullet is stable in flight and is not tumbling off to never never where ever. It does not mean that the flight of that bullet is straight and true. Take a .30 cal match bullet; out of one rifle it shoots 1/2 moa at 600 yards and out of a like rifle it shoots 3/4 moa at 600 yards. Are you then saying the 3/4 moa bullet is unstable?

All bullets have some degree of instability; they all have yaw, wobble or pitch or some combination. This is why we shoot groups instead of one hole. What we are discussing here is how bullets that are stable are also inaccurate. That is not an uncommon occurance even among jacketed bullets. Most military FMJ bullets being a good expample. Now let's get back to RPM and what is going on.

We know we have stable bullets out of the 10" twist barrel. Not perfectly stable but as stable as the same bullets at the same velocity out of the 12 and 14" twist barrels. The M43 measured the BC quite accurately. So what causes the same bullets that are capable of 2.5" groups at 200 yards at 1900 fps to go to 14.5' groups at 2500 fps? If the bullets were deformed it would, in fact, show up in a reduced BC. It didn't. If it was a "bad launch" then were saying I only "launched" the HV load badly? Considering the size of the 28 gr loads groups I think not. Considering the proportionately non-linear increasing size of the 38 gr loads groups, I think not. It remains obvious what is causing the inaccuracy; it is RPM. At some point within the RPM threshold that bullet at a certain RPM begins losing accuracy not stability. At that point accuracy, not stability, is lost in a non-linear fashion. At some point past 200 yards I believe the bullet also loses stability and will fly off into never never where ever.

BTW the M43 also prints out the time of flight in microseconds. They ran from 111132 to 109774. That's a difference of 001358 microseconds over the 10 shot string. I guess the time of flight is nice to know but it's actually the loss of velocity that is important. As in the example I gave of the M118 fired in two rifles, 10" and 12". The velocity loss was less with the 12" twist barrel. Ergo the BC was higher and the group was much better. Those are facts old boy. If you don't like them refute them with facts. But then you'd have to actually conduct a test by shooting a rifle instead of just pound away on your key board.

"Test results are nice, a brain is necessary. " Why don't you be "nice" and show us some test results?

I'm going shooting tomorrow, what are you doing?

Larry Gibson

[runfiverun]

larry
what i think leftiye is saying here is that a boolit [flyer] that is out of the group
has travelled an additional distance of .01.
and you showed that the m-43 measures this in time of flight? yes.

[Larry Gibson]

larry
what i think leftiye is saying here is that a boolit [flyer] that is out of the group
has travelled an additional distance of .01.
and you showed that the m-43 measures this in time of flight? yes.

Ok, so let me get this straight. The flyer in his 10" group flies one hundredth of an inch farther over 100 yards....and he wants to know if the M43 measures that? Is there a relevance to this? Is this the "how many angels can dance on the head of a pin question? We are talking a 10" group here right? And Leftiye is concerned about .01" additional travel? Over 100 yards? Well, all the bullets time of flight were measured. I did not track the hits on the target in relation to TOF or BC. However I did notice that most of those that were the flyers had the lowest BCs. Now if Leftiye is claiming the .01" extra travel as the reason the BCs are lower then he has really taken this from the sublime to the ridiculous.
Can the M43 measure that .01”? Maybe, maybe not, I really don’t know, what does it matter. All the bullets that were tested for BC in the Chapter 2 test went through the window of the skyscreens. Besides, if the bullet is a flyer 5” out then it is still a flyer 5” out whether it travels .01” extra or not. Is that deer 191 yards away or is it 192 yards away? What is the relevance to this?

Leftiye has made his stand. Nothing said is going to change his mind. He must continue to justify his position. When I started this test I said if the evidence proves the RPM threshold wrong I would admit it. Leftiye will not admit to anything. He is just hallucinating any kind of idea he can think of to discredit any test. He has failed to provide any data or documentation of his own that refutes the results of my tests or others tests.

I really don’t think I’m going to waste anymore time on his crap. I’ve said this before but I had hoped he would be reasonable. He didn’t have to agree but he should be reasonable. .01” extra travel at 100 yards….give me a break! Leftiye don’t even bother responding with more of this idiotic garbage.

Larry Gibson

[leftiye]

Larry, First off a little less attacking me personally please. I'm trying to be civil here, and I'm also having trouble figuring out why I can't get across what I'm saying. There is a huge amount of something here, none of which is germain to what I said.

I think that Run Five Run was on the right track maybe. I can afford to be wrong. Can you? I'm not staving off anything. But you will have to get on the same page here, or you haven't a chance of proving me wrong. The argument isn't about your machine. What I'm saying exists independently outside the machine. All we need to know is the smallest time of flight variation that results in a varied B.C. result.

It wasn't .010" difference in distance , it was .001, or .002" difference.

This is not "My Stand," it is only one of many issues that I have been seemingly unable to get you to comprehend. They are all unexplored by you, you dismiss them as "unnecessary," "ridiculous" etc without ever getting around to getting straight what is being said. As I said, I don't have to prove anything here. I don't have to be right. That is your problem. Defend your theory, or you'll end up claiming victory to an empty hall.

[Bass Ackward]

Larry,

Sheesh. My comment was that your word that they failed was good enough for me. Since you are going to post the pictures I assume you are going to do your best.

Back to absolutes are we? You sound as though you expect that you are going to see this effect each and every time? :grin:

Surely you didn't think that one test is going to prove or disprove RPMS? It only proves that you are experiencing RPM effect at that time, out of that gun, with that load, under those conditions. You have to test all the time. You may put that 38 grain load of 4895 in another 10 twist rifle and have it just do fine. Or that rifle may want a harder ................ or what will blow your mind, a softer bullet. Twist rate and RPM are NOT absolutes, that's what I see all the time.

Look at 300 grainers out of a 38 twist, 44 Mag. It is supposed to be mathematically impossible to shoot these. I have one that will, and one that won't. With the same loads, one key holes. So which RPM example is fact? The flaw is in the formula, not the mathematics. Remember, no facts in shooting.

And changing twist rate is not always required as in your handgun example. All Colts will not shoot every load with wadcutters just because you increased twist rate. The 7 grains of GreenDot load I quote to you is not stable out of my 4" Smith at 75 yards experiencing the RPM effect. But 7.5 grains of Unique that is slightly slower in velocity is stable and accurate to the same 75 yards.

Last Saturday's load that is 10" at 200 and non-linear by 400 will be MOA this summer. RPMs or not RPMs?

[Larry Gibson]

Leftiye

Your whole thought process is wrong. "Getting on the same page" with you apparently is nothing more than agreeing with you. It is my theory, I have conducted tests which prove it. I do not have to prove you wrong because you've done nothing. It is for you to prove me wrong and as noted; you've done nothing. You've got it ass backwards.

I've stated from the beginning that I could prove myself wrong and if so would admit it. So get off it about "can I afford it". You prove me wrong. Go conduct a test, come back with some facts.

Say something pertinant and I'll pay attention. Conduct a test and come back with facts and I'll pay attention. Show us where a .01" makes any difference in flight time. You say it does, I say it doesn't, who cares.

I've already proven me right. You prove me wrong with some facts. Don't come back with some idiotic concept.

Larry Gibson

[Larry Gibson]

Bass

Sheesh. My comment was that your word that they failed was good enough for me. Since you are going to post the pictures I assume you are going to do your best.

Thank you, I'll accept that.

Back to absolutes are we? You sound as though you expect that you are going to see this effect each and every time? :grin:

Yes, with that load I would expect to see it each and every time. Actually I have seen it each and every time for years. About every time I push a regular cast bullet past the RPM threshold I see it. Every time anyone else pushes a regular cast bullet past the RPM threshold they see it too.

Surely you didn't think that one test is going to prove or disprove RPMS? It only proves that you are experiencing RPM effect at that time, out of that gun, with that load, under those conditions. You have to test all the time. You may put that 38 grain load of 4895 in another 10 twist rifle and have it just do fine. Or that rifle may want a harder ................ or what will blow your mind, a softer bullet. Twist rate and RPM are NOT absolutes, that's what I see all the time.

Let me quote YOU;


“Larry should use the same top end loads that he did in this test that the slow twist performed better than the fast. Keep this simple. We know that the slower twist is going to shoot these more accurately, he already proved that. Right now we are drawing the conclusion that it is RPMS that is the reason.

If groups are radically bigger with the faster twist rate at 200 than they were at 100, then Larry has proven the RPM theory. If the groups from all twist rates are all linear, then RPMs was NOT the reason for the inaccuracy.

Let's identify the enemy that needs fought.

Added: Really Larry only has to do this with the 10 twist at first. It should be the WORST of the three twist rates. If it is wild, then he has satisfied me and he can continue with the other twists if he wants. If the 10 twist is poor, but still linear, then why waste his time and components? Cause RPMs won't be the problem.”



YOU said this test would prove it was RPM and I agreed. Now you renege and say it doesn’t or it only applies to the one test. Yes I do believe it will happen every time. I have been shooting that load or similar ones for 40+ years and it always happens.

So you want to test long enough until you finally get one group where the bullets randomly go close together and then yell “eureka” I’m the king of HV cast bullets. How convenient then to ignore all the previous bad groups. Horse manure, if it happens once out of many, many times that is an anomaly and proves nothing. Testing until you get one good group is not valid. Being able to shoot good groups over and over on any day is valid. Hard bullets, soft bullets? Let's make up our mind. Fact is the softer bullets shoot much worse, I’ve already been there and done that. So has most every shooter of regular cast bullets who has pushed them above the RPM threshold including you.

If you see that “twist rates and RPM are not absolutes” all the time then how about you conducting the same test I did with your rifle (your 10” twist ’06 will do fine as the exact same thing will happen with 311291 at 2500 fps) and report back. If you conduct the test you’ll have confidence in what you say. If you don’t conduct the test then it’s obvious you know you’re wrong.[/B]

Look at 300 grainers out of a 38 twist, 44 Mag. It is supposed to be mathematically impossible to shoot these. I have one that will, and one that won't. With the same loads, one key holes. So which RPM example is fact? The flaw is in the formula, not the mathematics. Remember, no facts in shooting.

What is it with you and Leftiye? You both keep coming up with non-sensible examples that are meaningless to this test. In order for your 300 gr .44 bullet out of a 38” twist to enter the RPM threshold at 125,000 RPM it would have to be doing 6,491 fps. Since your "example" doesn’t do that kind of velocity/ RPM and isn't even approaching the RPM threshold let alone going through the RPM threshold your "example" doesn’t apply. It is a very poor example (one of many such poor examples) for this discussion. Come back with an example that is through the RPM threshold so it applies to the question here. Let me refresh your memory; the RPM threshold is 125-140,000 RPM. So give us an "example" of a regular cast bullet that shoots as well or better above that RPM threshold than it does below it. That kind of an "example" is germain to this question. Your .44 "example" is not.

Your .44 example is simply about rotational stability and what is required to attain it. Two rifles, same load but you don’t mention the velocity out of each rifle. One may be only a few fps faster than the other. That would be all that is required for the bullet to become rotationally stable.

Please stick to the point here; that is about the adverse effect on accuracy when a regular cast bullet goes through the RPM threshold. I really am tired of all these “examples” that do not apply.

And changing twist rate is not always required as in your handgun example. All Colts will not shoot every load with wadcutters just because you increased twist rate. The 7 grains of GreenDot load I quote to you is not stable out of my 4" Smith at 75 yards experiencing the RPM effect. But 7.5 grains of Unique that is slightly slower in velocity is stable and accurate to the same 75 yards.

Your load is not “experiencing the RPM effect”. Just how fast would you have to push that WC out of that 4” barrel for it to be doing 125,000 RPM? Your WCs are simply dropping below the minimal velocity necessary for stable flight. This is just another "example" that does not apply. A bullet ataining or losing rotaional stability is not what we're discussing or testing for. We are discussing the adverse affects on accuracy that occur to a regular cast bullet as it goes thorugh or beyond the RPM threshold. How may times must I repeat this before some understand.

Last Saturday's load that is 10" at 200 and non-linear by 400 will be MOA this summer. RPMs or not RPMs?

That load does you one hell of a lot of good today doesn’t it? A load that is only good on hot days and then only if you shoot 1 or 2 shots an hour….that’s sure what every other cast bullet shooter wants. Also (we’ve been through this many times already) you are using a custom designed bullet for the ’06 length neck and throat. So what does that have to do with (here goes the “question” again) how RPM adversely affects the accuracy of a regular cast bullet when pushed through the RPM threshold. It has nothing to do with it.

I am still quite disappointed in your reneging. Why don’t you conduct the test with 311291 now and show us all how easy it is to get accuracy at 2500 fps?

Larry Gibson

[leftiye]

Larry, NO, my thought process is fine. It may not have the effect I think it will have, but that can only be shown by you providing the info requested.

Bass, we should let this guy function in a vacuum. It is apparently all he is capable of.

[Larry Gibson]

Leftiye

Another idiotic response and pretty self rightous too. And please "a little less attacking me personally"! Actually it might be better if you did leave me in a "vacuum". I could then get on with the tests instead of attempting to reason with you and answering your non-sensible questions.

Larry Gibson

[leftiye]

[Show us where a .01" makes any difference in flight time. You say it does, I say it doesn't, who cares.] Larry gibson

This above, Larry, is what "idiotic" looks like.

You don't even get the numbers right. And this after I've corrected you several times. I didn't say it made a difference in time of flight except to ask you how long it takes your boolit to travel .002". I told you your machine couldn't measure this distance as time of flight. It in all likelyhood can't. There's hardy anything that can. If you would stick to what is said, and not distort it........ Oh, well. But that's what you call winning arguments, Isn't it?

[Larry Gibson]

Leftiye

What difference does the .001/.01 or .002" more travel because a bullet hits 5" to the left make? Explain that to us. The fact that it can't be measured (you don't know that) is meaningless because that .00whatever is meaningless.

This question/example of yours is just BS and is a smokescreen or red herring. It has absolutely no meaning to what we're testing for. Besides you've not mentioned the phase of the Moon and how it's gravitational pull effected the group. Then you also missed the angle of the range in relation to due North and how the Earths spin effected the group. Then of course you also missed how I parted my hair the morning I ran the test and how that effected the group. I'm sure you have numerous other non-sensible things to bring up.

"I didn't say it made a difference in time of flight except to ask you how long it takes your boolit to travel .002"

You contradict yourself; how long a bullet travels is time of flight. An intelligent individual understands that. And if it doesn't make any difference then why are you bothering us with such nonsense about measuring it.

If you can't come back with facts or at least conduct your own test to refute mine regarding the RPM threshold then please leave me in my vacuum.

Larry Gibson

[BABore]

Larry,

You keep referring to "Regular" cast bullets. Could you please define them for me. You see I haven't been casting for very long and am afraid I might have missed something here.

In my short casting career, I was taught to cast boolits that were a good to perfect fit to the firearm's chamber, throat(s) and groove. They should be cast from an alloy and alloy hardness that is suitable for the velocity and pressure your looking for. And they should be cast with a proper technique to achieve extremely low weight variation.

I was also taught that all of my prior reloading experience had to evolve. I now had to add bullet lube and the above mentioned alloy/hardness variables into the process. They all had to be treated as reloading variables along with the normal jacketed bullet ones. Everything is interrelated and has to be tested one variable at a time, until success is achieved. Most importantly, I was taught that as you increase velocity, things change, and variables have to be changed to handle it. There is no wonder bullet, alloy, hardness, lube, etc. that will cover the LV to HV range.

So, being inexperienced and generally ignorant compared to those with such vast casting/shooting experience, am I making "Regular"cast bullets? What I am confused about is the way you are conducting your test, is the opposite of what I was taught. Your using a normal bullet, alloy, hardness, and lube for the LV testing, but make no accommodations or changes when you increase velocity. From what little I've learned, this seems like exactly the opposite approach if you wanted HV success. Or is/was that the plan. You claim that your keeping an open mind. That's noble. Yet from Chapter 1 you told us what the outcome would be. When I and others brought up alloy hardness, lube, etc., you said that would be in future tests, yet you just said you already proved your theory. That sounds very biased to me.

[leftiye]

[Leftiye'
What difference does the .001/.01 or .002" more travel because a bullet hits 5" to the left make? Explain that to us. The fact that it can't be measured (you don't know that) is meaningless because that .00whatever is meaningless] Larry Gibson

So I should do what so you can understand?

The point is THAT IT DOESN'T MAKE A DIFFERENCE! the extra several thousandths of an inch and its effect upon time of flight is too small to measure. If it cam be measured at all, it is too small a time quantity to have effect on B.C. calculations. The boolit can deflect vast distances (in group size terms) before it flies enough further that it makes any difference in B.C. So, again, what is the smallest increment of time your program requires before a difference in B.C. will register?

[Larry Gibson]

Leftiye

Let me explain the absolute absurdity of what you are talking about. You are discussing the horizontal difference based on a point of impact different from the center if aim. That distance may be .001 or whatever horizontally from the axis of flight. Now first of all that .001 or whatever is only valid if, let me say that again, if you can absolutely guarantee the muzzle is in the exact position as it was for the shot before. Are you that good that you can guarantee the exact positioning of the muzzle each and every shot? No you are not. I am not. As a matter of fact I doubt that anyone is. So if the muzzle was just .01 farther forward it means the flyer in your example actually traveled .009” less. Thus it did not travel further as you’ve speculated.

Then consider the M43 measures shots that go through the relatively narrow (anyone who has shot his chronograph can appreciate how small that window must be at 100 yards) window of the skyscreens. The M43 measures the TOF of the bullet which is parallel to the axis of aim and it does it with a great amount of precision. In the case of how I set up the screens the actual measured distance is 284 feet. A .001” deflection of a flyer to the side is an error of 0.00000029% over that distance. And that is only if you can guarantee the muzzle is in exactly the same position each time, which you can’t. We all fail to see your point in this.

"The boolit can deflect vast distances (in group size terms) before it flies enough further that it makes any difference in B.C."

The M43 measures the TOF between between the two sets of skyscreens which are 284 feet apart and parallel to the axis of aim. That is the distance that is measured to obtain the BC, not the slight distance of divergence horizontally to the axis of aim. 284 feet is quite enough distance for the M43 to measure the muzzle velocity, the TOF, the remaining velocity and then very accurately compute the BC.

So I’ve got to ask the obvious; since you state rather emphatically “THAT IT DOESN'T MAKE A DIFFERENCE" and we all agree with you, why then are you wasting our time with this absurdity when it doesn’t matter? Some would think you doing that is pretty stupid.

Larry Gibson

[leftiye]

Time to travel .002" @ 2500 fps. = .000000067 second. Way less than .07 millionths of a second (reads 7 hundredths of a millionth of a second).

[Larry Gibson]

Leftiye

Like you said; "The point is THAT IT DOESN'T MAKE A DIFFERENCE". It would be nice if you would pay attention to your own point.

Larry Gibson

[leftiye]

Yeah, but it DOES make it impossible to use B.C. calculations to determine if instabiity , or deformation is taking place.

[Larry Gibson]

Leftiye

That is your opinion. Do you have a M43? Do you use a M43. Did you design the M43 or it's computor program? Do you even have the manual for the M43? The answer to these questions is NO.

It is very possible because given the same load with the same bullet at the same velocity the bullet with the lower BC is a less stable bullet. The lower BC means it is not flying as efficiently through the air as a same bullet that gets a higher BC. That is common knowledge to anyone who studies ballistics. The M43 measures these small changes in BC based on the actual measurement of the bullets flight. Your meaningless idea of .001 more travel is quite stupid. You also are avoiding numerous question put to you. Are you good enough to exactly place the muzzle so a .001" difference in latteral dispersion can be measured 100 yards away?

Now unless you can come up with some proof other than your own opinion let it go. As a matter of fact it would be nice to see you come up with anything like facts or groups or the results of tests other than your opinion and meaningless ideas.

Your continued denial of conducting tests or posting shooting results and constant referral to others works and/or opinions is making me wonder if you even own a rifle let alone cast bullets and shoot them.

Larry Gibson

[EDG]

Larry,
I just found this thread and my eyes don't have the stamina to read all 27 pages. So I may have missed it if someone has mentioned the load data that is on the internet posted by Greg Mushial.

http://www.gmdr.com/lever/lowveldata.htm

Several years ago I slogged through his graphs looking at the best groups vs velocity (last graph per caliber). I noticed that there was a trend for some of the faster twist rifles to not group as well as the slow twist calibers. Within a given caliber it seems there was velocity threshold where his groups went to pot with most if not all the powders. That velocity threshold tended to be higher for some of the slower twist barrels.
The rounds most comparable in case capacity are the 30-30, 32 Special, .35 Remington, and the .375 Win. The rifles he used have 3 different twists. I won't say there is anything conclusive from my observations but some torturing of the data might prove it one way or the other. Your testing is may give the answer.
FWIW

[leftiye]

Wrong again Larry. Denigrate away, that appears to be all you're capable of. No, beyond being my opinion, it is a logical impossibility. Better still, it's a simple logical impossibility that perhaps only you fail to see. Or you might better say, a mechanical impossibility. Surely, anyone curious about it could investigate and come to the proper conclusion. If the difference in time of flight is less than will show up in a change of B.C. on a given computer/sensor system, it cannot/will not reflect a change of B.C. Not quite one of your fallacies against definition Larry, but close. It would violate the design capabilities of your machine. Is that why the smallest increment of time that your machine/sensors/program will register a variance in B.C with is such a closely guarded secret?

[leftiye]

Everybody, Let's take a poll. How many think that corkscrewing boolits are stable? What is YOUR belief concerning the definition of "Stable flight" as concerns boolits? Do they wobble? Do they yaw? Do they corkscrew? Tap dance? Yes, this is germaine to the present issue, if you wondered. I'd appreciate your answers.

[Larry Gibson]

Leftiye

"Is that why the smallest increment of time that your machine/sensors/program will register a variance in B.C with is such a closely guarded secret?"

The capability of the M43 to measure is very plainly spelled out by me in a prior post. I'm not going to say you're stupid but to quote the movie; stupid is as stupid does. Try reading the posts before you make stupid statements.

I've wasted enough time on you.

Larry Gibson

[leftiye]

Baloney! Please just tell me, go ahead in the present case and since I am so stupid, HELP US OUT.

[Larry Gibson]

EDG

Thanks for the post and interesting information. With the exception of a 3 or 4 here you have observed what most everyone else has. There is a RPM threshold with most any regular cast bullet. In rifles I have used cast bullets in .22H, .222, .223, 22-250, .243, 25-20, 257R, 6.5 Jap, 6.5 Swede, 6.5-280, 7x57, 280R, 30 Carbine, 30-30, 308 CBC, 300 Sav, 308 W, 30-06, 7.62R, 7.62x39, .303, 7.65 Arg, 8x57, 8-06, 35 Rem, 358 W, 35 Whelen, .375 H&H, 45-70, 45-90, 45-110, 50-70 and 458Win Mag. In each of them with a 14" or quicker twist the accuracy always went south at a certain velocity as you noted. It was never the same velocity and this perplexed me for some time. Then I read a couple articles that referenced the adverse effect RPM might have. Since I have been chronographing loads since '75 I had accumalated some data. A check of that data showed that accuracy always went south somewhere in the 125-140,000 RPM range. I began to refer to that as a threshold. Over the years it has proven to be a threshold with regular cast bullets. I found that it is very difficult to cross through that threshold and maintain any degree of decent accuracy. The best accuracy also always occurs below or in the RPM threshold. I am attempting to measure a lot of things and to prove the existance of the RPM threshold one way or the other. As you can see I have a lot of supporters and a few detractors. However it is the results of the test that will confirm it one way or the other. So far the tests are confirming the RPM threshold.

Thanks again, hope to hear from you again.

Larry Gibson

[runfiverun]

since i cannot do the math for the rpm's i do it with velocity.
it is not going to stop me from tryig to get accuracy at hv with my 308, cause i am kinda
like that,
but i am going to enjoy shooting nice groups with my other stuff within the threshold,
however it is defined or what it is called.
and that last DISCUSSION was ....well.....it just was..

[Larry Gibson]

runfiverun

Do keep pushing the RPM threshold. The threshold is there and it is not a barrier. It is not easy to get through and have decent accuracy at HV but it can be done. I seriously doubt we will make much progress with regular cast bullets though, particularly ones with long bore riding noses. I have tried all sorts things (most all that have been mentioned in this thread) numerous times before with only minor success. In the up coming RPM tests I also am going to push the RPM threshold. I will do it primarily with 311466. It is a lovern design that is very close to the LBT design Bass has. My goal is 2500 fps with decent and consistant accuracy of 1.5 moa with the 10" twist with 5 shot strings. When I get a good consistant load at that velocity I will then change just one thing at a time. Anyways, hang in there.

Larry Gibson

[Tiger]

Larry and EGD

Big thing I see with website EGD post is all powders extremely fast ones. We all know that all those calibers get good accuracy with more slow rifle powders and at much higher velocity then what site had. Interesting website and information yes prove anything to rpm thresh hold here...no.

Ralf

[Larry Gibson]

Ralf

I don't believe either EGD or myself said that site proved anything. It was a discussion of what infoormation was there. Also there was a good amount of 2400 and 4227 used. I've experienced plenty of RPM threshold with those two powders over the years.

Larry Gibson

[leftiye]

Larry, you should have experienced plenty of boolit deformation with those powders at high velocity. Also, lots of unstable flight and lots of aerodynamic deflection. Go ahead, more character assassination please.

[joeb33050]

Bullets have these three kinds of motion that affect accuracy. Yaw is the movement of the long axis of the bullet. Nutation is the movement of the bullet in small diameter circles. These are what Dr. Mann called the a and B movements or accuracy-affecters.
Precession is the movement of the bullet over a cone-shaped path, movement in diminishing diameter circles. Precession may cause groups to diminish in size as range increases.
These three kinds of motion are well understood and explained in excruciating detail at dozens-hundreds of sites on the web.
One can argue, or look it up. Your choice.
joe b.

[Bass Ackward]

Larry,

I think this has become totally nonproductive. It has gone for a search, to one where nitpicking in writing is the driving force on many sides and I don't think we can work passed that at this point.

Since I have nothing else left to offer here for now of any value, I am going to end my participation.

For the record of my current opinion: I do consider RPMs now as a possible cause. But not the overwhelming one. It is just in the mix with pressure and air and everything else. I will test for it now though before I finalize my load for close in accuracy. That is what I have gained though this thread.

I have said all along, that the easiest accuracy occurs at the lowest velocity that you can fulfill all the requirements. It allows the most errors from the molding, reloading, and shooting processes. That is true from handgun to rifle at low RPMs or high.

If you don't want to alter or change anything with cast and simply want them to perform like jacketed, you are going to produce worse results as you climb the velocity ladder in anything unless you shoot hard bullets exclusively. The old adage of using the slowest twist rate possible to stabilize is still true. Is that RPMs in the air or RPMs up the pipe? Failure to match hardness (if possible with lead) to what you are doing trivializes errors also, but is not a requirement for HV accuracy.

If we still do or change something to correct what is wrong, this discussion disappears as accuracy is the result. How good that accuracy is, still depends on what you are willing to do to get it. And that is the whole point to cast and reloading really. If you don't want headaches, stay in the zone as you call it or shoot jacketed.

That's summarizes my current opinion for the record.

[Larry Gibson]

Larry, you should have experienced plenty of boolit deformation with those powders at high velocity. Also, lots of unstable flight and lots of aerodynamic deflection. Go ahead, more character assassination please.

Leftiye

Don't be so paranoid, when you think logically and use facts you are always correct; as you are in this case.

Let me note that the RPM threshold covers 125-140,000 RPM. With2400 and 4227 in a 10" twist I've found they begin to lose accuracy in the lower end of the 1700 fps range. They actually quite accurate with medium/heavy cast bullets in the 1500-1600 fps range. 125,000 RPM is generated arond 1735 fps in a 10" twist.

The two powders mentioned do create more deformation at that top end which is in the lower end of the RPM threshold. There also is lots of "unstable flight and lots of aerodynamic deflection" as you mention. This because the deformed (unbalanced) bullets are adversely affected by the RPM within the RPM threshold.

So you see, you are very correct here. Only you need to see and understand it. Thank you for your observation.

Larry Gibson

[leftiye]

Yup, and most of the things that cause inaccuracy still probly fly under your radar because - A. they don't increase time of flight enough to register on your B.C. calculations. I don't actually have to prove this by showing how far a boolit can fly before your machine notices. Your machine hasn't noticed any yet, and it's certain they've been there, look at the accuracy. B. You think that yawing, corkscrewing boolits can be called stable.

And as per your post to Bass yesterday, you knew going in to the trajectory test that that particular load had always gone to h@!! at over 100 yds distances when fired out of a 10" twist gun.

A yawing boolit doesn't require high RPMs to deflect by air resistance. It only needs to rotate against the oncoming air to become a corkscrew. High Rpms actually helps the boolit to precess back to stability because the spiral has a narrower, shorter period due to the High Rpms.

Also, please educate us as to how a bullet flying straight on can fly in a spiral.

[felix]

A boolit that does not rotate will not overcome any kind of yaw/corkscrew. The amount of yaw/corkscrew should not enter into Larry's analysis. Hopefully, they do not cause any blurring of the results he is after. ... felix

[Larry Gibson]

Bass

Thank you for your participation. It has always been interesting and thought provoking though a little frustrating at times. I feel we made a real leap forward with that last test you suggested. I shall fast forward away from 311921 and work with 311466 to see where the RPM threshold adversely affects it and then begin testing on what specific things we can do (tested one at a time) to see what it takes to get through the RPM threshold with acceptable accuracy. I also will see just how far we can push it. The interesting part will probably be with the 14" twist but I'll wring out the 10" twist just to increase our knowledge.

I too have tried to back out of this thread several times but someone always seemed to come up with something worthy of continued discussion (like EDG and runfiverun - even Leftiye and Ralf). It seems it mostly is just bickering now so I will cease posting here also.

I think you and everyone else knows my stand on this issue; I do believe there is a RPM threshold for regular cast bullets. The facts of the tests and many years of not only my experiences but everyone else's experiences says there is. We must remember that a "threshold" is not a barrier or wall, it can be passed through but it is difficult to do. There are few regular cast bullet moulds that will alow us to do this. Those cast bullets with long bearing surfaces, short noses and small lube grooves seem to be able to pass through the treshold. Such bullets are your LBT design and the shorter Lovern designs. I still have a few of your LBTs to test again and may end up getting a mould for it as you suggested. I also have high hopes for the 311466.

We've had many good and intersting conversations Bass and I hope for many in the future. I'll close out with one last statement. If the tests demonstrate that the RPM threshold does not exist and it is not RPM causing the inaccuracy of the bullet during flight then I will be the first to admit I was/am wrong.

Larry Gibson

[leftiye]

Felix, I agree. However no one postulated that the boolit not be rotating. Only that high rpms are not the thing producing corkscrewing. Yes corkscrewing will enter in, it will produce inaccuracy which should not be attributed to rpms. Blurring if you will. Not all rotating boolits overcome the corkscrewing. Some fly away to parts unknown.

[felix]

True! Corking comes from barrel vibes. Corking can be minimized by either using a lighter boolit or a heavier barrel at the same length. Preference is given to a barrel of length 21.75 inches, no matter what the caliber or barrel weight. This comes from the warehouse experiments over several years with different gun configurations, while using middle speed powders for the most part with medium to light bullets for the caliber, and using appropriate twists for the payload. Yawing comes from too much pressure at the muzzle for the diameter and weight of the projectile. ... felix

[runfiverun]

i totally agree with felix on the yawing.
it is just like throwing a football wiyh your finger on the end of it.

[Larry Gibson]

Well, stupid is as stupid does again.

Leftiye

In case you can't read I'm through trying to explain things to you. In case you can't read I've explained it over and over and over to you. Are you really too stupid to understand?

One last time (got that...last time). All bullets yaw, pitch or wobble. Some more than others. the ones that do any one of the three or a combination of the three are more inaccurate than those that do one or more of those to a lesser degree. Its why we shoot groups instead of all bullets going into one hole.

Now, just because a bullet may have one or more of those three doesn't mean it is unstable in the sense the bullet does not fly point on and will follow a trajectory. A bullet that loses stability is the one that flies off into never, never land. All bullets that are fired have some degree of instability from very little to totally unstable.

A bullet can fly point forward in a spiral path around the center of it's trajectory because it has more weight on one side of its center of form. It may also be yawing pitching or wobbling. It is quite possible because it does happen. You were/are one of the proponants of bullets "going to sleep". If the bullets are not spiraling around the axis of trajectory how is it that groups are larger at 100 yards yet closer at 200 yards? I don't yet buy off on the 'going to sleep" theory but am open to some one proving it through tests. That completes your education for today as requested but I tire of having to continually give you the same lessons out of "Ballistics for Dummies" over and over and over ad nauseum.

BTW; Yes I did know what would happen at 50 yards, 100 yards and 200 yards with that load. I have shot that load many many times over the years trying to get some accuracy out of a 311291 at 2500 fps. But remember this; I did not suggest the test, I did not pick the load, I did not pick the twist of barrel for the test, Bass picked them. He also said if the groups opened in a non-linear way then it was RPM. I did not see you jump in there and cry foul. I did not see any objection from anyone that that would not prove the theory on RPM. Only after the test proved it was RPM and not what you wanted it to be did you or anyone else object. Bass has renegged and you still are whining about it. Sorry dude, facts are facts whether they fit your preconcieved ideas or not.

Now, why don't you be a nice little boy and take your football home for a while. In a few weeks I will have another test completed and you can come back out and complain about the game then. In other words; I tire of this, Bass is tired of it and so are most others. So just let it go for a while, we'll meet again in the next chapter.

Larry Gibson

[Larry Gibson]

True! Corking comes from barrel vibes. Corking can be minimized by either using a lighter boolit or a heavier barrel at the same length. Preference is given to a barrel of length 21.75 inches, no matter what the caliber or barrel weight. This comes from the warehouse experiments over several years with different gun configurations, while using middle speed powders for the most part with medium to light bullets for the caliber, and using appropriate twists for the payload. Yawing comes from too much pressure at the muzzle for the diameter and weight of the projectile. ... felix

Felix

I agree with you that corking can come from barrel vibes. However those that come from barrel vibes still produce linear groups as the range increases. Bad groups though they can be they still are stable bullets. What the test I ran at Bass's suggestion proved that those groups opened up in a very non-linear fashion. The centrfugal force of the higher RPMs over came the rotational stability (Leftiye, that doesn't meant the bullet was completely unstable) and the goups opened up in that non-linear fashon. The groups from the lower velocity load opened in a completely linear fashion because the RPMs were not high enough to generate sufficient centrifugal force to over come the rotational stability of the bullet. That is the basis of the RPM threshold. The test did prove it just as Bass said it would.

Larry Gibson

[Larry Gibson]

i totally agree with felix on the yawing.
it is just like throwing a football wiyh your finger on the end of it.

Quite true, yes those kinds of throws still go down range for the ends to catch. They are not as accurately thrown as the perfect spiral pass but they sill go down range where intended. Both are stable but one is more stable than the other. How well does the football fly when it goes end over end? It does not fly well nor accurately. Pretty much the same with bullets.

Take a M80 ball bullet in your .308. How well does it shoot? 2-3 MOA? Certainly not as accurate as a 150 gr MK, eh? So what is the difference? The difference is in the quality of the bullet which effects how well it shoots. What does that mean? It means the MK is made to much more uniform standards than the M80 bullet. When the MK is fired the center of gravity will be much closer to the center of form. The MK and the M80 bullet both may also yaw, pitch or wobble. The more uniform balance of the MK means it will yaw, pitch or wobble to a much lessor degree than the M80 bullet. That translates into much better accuracy for the MK because it is more stable in flight than the M80 bullet. That is not to say that either bullet is unstable is it? It just means that one bullet is more stable than the other, just like the two football throws. The difference in stability shows up in a measured BC. Contrary to Leftiye the M43 can and does measure such differences.

Larry Gibson

[felix]

I said what I said for you to see, Larry! The suggestion is for you to try and find a range or boolit for your experiment(s) where corking does not show up to any destroying extent. It is extremely difficult to find a acelleration curve which can make any heavy boolit exit the barrel exactly between two nodes. Finding an optimum range distance for each gun would be easier. In either situation, trying to prove the RPM threshold theory, as an independent variable, at the 90 percent confidence level is tough, but that is the name of your game here. Keep up what you are doing, and some magic will pop out, either pro or con. ... felix

[Larry Gibson]

Felix

Excellent! I am hoping the 311466 with it's long bearing surface and short nose can be that bullet. The LBT bullet of Bass's is real close too. It is designed to just fit in the neck of an '06 with the base of the GC at the base of the neck and the ogive to just bump into the leade. I'll see if I can't attached a picture of the 311466 along side the LBT bullet again. Gine me some thoughts on the potential here.

Couldn't find the side by side comparison but here's a picture of each. The 311466 on the left is at .314" and the right bullet is the 311466 sized down to .309". I can test them at .314, .312, .311, .309 and .308".

Larry Gibson

[felix]

Larry, go for it! Use 'em both, but I would start with the 14 twister, and adjust the range for each boolit. Could be 80 yards for one, 110 for the other, and their harmonical distances in between and beyond. ... felix

[runfiverun]

larry
i have a 310 and a 313 sizer these are for a star
if you need/want to try some at this size.
i am working that 28 gr load to death going to compare some partial length n/sizing, heads
up with full neck next.
it shot a 2"wide x 3" high today at 200 but i had about a 10 mph wind from 5 oclock
i was tyring to dope.
took it over to the silhouette range and it took the 200meter rams right down
and was holding a straight line at 300 hit 12x12 gong 4 out of 6 times with two shots just a bit low.
350 rounds so far no cleaning except 1 dry patch and still 1" groups at 100 yds.
p.s. hot-core aint happy.

[runfiverun]

i think what felix said about the range is kinda the same as i talking about
on my twist test, when i got bass to throw me those numbers, i wanted to see if i could see
something happen ,by moving a target further and further away, so i could SEE it.
then put the no's with it.

[leftiye]

Take a M80 ball bullet in your .308. How well does it shoot? 2-3 MOA? Certainly not as accurate as a 150 gr MK, eh? So what is the difference? The difference is in the quality of the bullet which effects how well it shoots. What does that mean? It means the MK is made to much more uniform standards than the M80 bullet. When the MK is fired the center of gravity will be much closer to the center of form. The MK and the M80 bullet both may also yaw, pitch or wobble. The more uniform balance of the MK means it will yaw, pitch or wobble to a much lessor degree than the M80 bullet. That translates into much better accuracy for the MK because it is more stable in flight than the M80 bullet. That is not to say that either bullet is unstable is it? It just means that one bullet is more stable than the other, just like the two football throws. The difference in stability shows up in a measured BC. Contrary to Leftiye the M43 can and does measure such differences.

Larry Gibson

I think that a boolit is stable when it is like a top that has settled down - no wobble, or anything else, (I think that is the definition of stable), or else it is unstable to some degree. The fact that a boolit hasn't yet departed for parts unknown doesn't define it to be stable. It may at this point be semantics.

But it is not semantics when all of this instability before being out of control is classed as being stable - as Larry does here, and in his test, - then virtually all instability has been defined as being stable (and disappears from the playing field), and all inaccuracy results can then be attributed to RPM effects.

I'd be appreciative of hearing the general opinion on this (what is your definition of stability).

"The more uniform balance of the MK means it will yaw, pitch or wobble to a much lessor degree than the M80 bullet. That translates into much better accuracy for the MK because it is more stable in flight than the M80 bullet." L.G.

It further seems to me that Larry here gives the standard definition that includes inaccuracy as being attributed to these minor instabilities (as well as admitting that they do cause inaccuracy - which he does nowhere in his test without attributing it to rpms).

It must be noted that out of balance, and RPMs do not cause all pitching, yawing and corkscrewing - as Felix stated in his previous post.

[Larry Gibson]

Leftiye

I see you just can't go home and leave it alone.

"It further seems to me that Larry here gives the standard definition that includes inaccuracy as being attributed to these minor instabilities (as well as admitting that they do cause inaccuracy - which he does nowhere in his test without attributing it to rpms)."

Lesson #2 today out of "Ballistics for Dummies" just for you. I have stated throughout this thread and others that without RPM and it's attendant centrifugal force all bullets would fly straight. It is the "minor instabilities" that are adversely affected by the RPMs centrafugal force which cause inaccuracies. This of course in a windless atmosphere as the wind also pushes bullets around. Given a perfectly balanced bullet that is rotaionally stable and there is no yaw,pitch or wobble.

Also I never said that only RPM caused inaccuracy. I've constantly refered to stable bullets in flight. Yaw, pitch and wobble also cause inaccuracy. However as discussed and told to you before. Those typse of inaccuracy are linear in dispersion at farther distances. As the test that Bass suggested proved the inaccuracy I'm talking about is non-linear at farther sistances. Try understanding that and quit coming up with this dum and dumber crap over and over again. If you disagree with it prove it. To keep asking the dumb same question or making the same dumb statement over and over again is, well, dumb.

Now that you have established yourself as asking dumb questions I'll answer another one for you. Actually I won't answer it Sierra's ballisticians will. The last part of this post is quoted from the Sierra publication "ExteriorBallistics.com". It answers you question about "what is your definition of stability". You might also note (that is if you're smart enough this time) that they are conducting tests to determine bullet stability the very same way I am. Maybe you'd like to email Sierra's balisticians and ask them all the same dumb questions you've ask me. Maybe also you'd like to tell them their test isn't valid because they can't measure the subtle differences in BCs. Then you'd reallt have a reputation for being dumb. But then what do I know, eh? Just read on what the Sierra ballisticians are doing. and then ask yourself if it's any different than what I'm doing. You'll probably just amaze yourself with the answer.

Larry Gibson

From Sierra's Exterior Ballistics.Com. You can read the whole article at http://www.exteriorballistics.com/ebexplained/5th/25.cfm

It is well known that bullet stability is critical for accuracy, but it is not well understood that there are different degrees of bullet stability. BC measurements give us some insights into varying degrees of bullet stability. Figure 2.5-2 shows BC measurements for Sierra’s 22 caliber (.224 inch diameter) 69 grain Hollow Point Boat Tail MatchKing bullet as a function of rifling twist rate. The rifling twist rates in the test barrels varied from one turn in 7 inches (1 x 7) to one turn in 12 inches (1 x 12), except that we did not have a test barrel with a 1 x 11 twist rate. All BC measurements were made by the initial velocity and time of flight method. All rounds were fired at around 2800 fps, which is about a maximum load for this bullet in the 223 Remington cartridge in a bolt action rifle. The figure shows the number of rounds fired at each rifling twist rate and the individual BC measurements for each group, together with the average value, the standard deviation (SD), and the extreme spread (ES) of the group.

Looking first at the group for the 1x 7 twist rate, the average BC values for this group of 10 rounds is 0.297 when rounded to three significant figures, sufficient for trajectory computations. The standard deviation (SD) of the measurements, 0.0022, is less than 1.0 % of the average BC value for the group, and the extreme spread (ES), 0.0079, is less than 4.0% of the average BC value. These figures illustrate the criteria that we use (SD no more than about 1.0% of average value, and ES no more than about 5.0% of average value) to determine whether the measured data are “good.” If either of these criteria is seriously exceeded, we look for a reason or repeat the measurements.

The 12 round group for the 1x8 twist rate also has an average BC value of 0.297. The standard deviation for the group is 0.0039, which is about 1.3% of the average BC value, and the ES, 0.0129, is about 4.3% of the average BC value. This group obviously is not quite as “tight” as the previous group, but we would not call this “bad” because the SD does not seriously violate our standard deviation criterion.

The groups for the 1x9 and 1x10 rifling twist rates also satisfy the stan-

Figure 2.5-2. BC measurements versus barrel twist rates for Sierra’s



dard deviation and extreme spread criteria, but the average BC values are beginning to decrease. For the 1x9 twist rate, the average BC is 0.295, and for the 1x10 twist rate, the average BC value is 0.294. The group for the 1x12 rifling twist rate shows a striking decrease in average BC value and increase in the scatter in the measurements. We attribute these changes to a decrease in stability of the bullets fired from the barrels with the slower rifling twist rates. We emphasize that none of the bullets tumbled during flight; all bullets printed point-first on paper targets just behind screen 3 in the test setup (see Figure 2.3-2).

Our interpretation of the data is as follows. All bullets have some coning motion just after they leave the barrel, as described in Section 2.4. When the rifling twist rate is fast (e.g., the 1x7 and 1x8 twist rates in Figure 2.5-2), the coning motion is small, and the dominant causes of the scatter in the BC measurements are random sources of error such as those described in Section 2.3.1.2. When the rifling twist rate in the barrel is slower (e.g., the 1x9 and 1x10 twist rates in Figure 2.5-2), coning motion increases in magnitude, and it becomes a systematic source of BC measurement error. This systematic effect causes the average value of the BC measurements to decrease, while the scatter in the measurements, caused by random sources of error, does not increase dramatically. In other words, the increased coning motion causes all the bullets to experience increased drag, and on average, they experience the same increase in drag, which causes a reduced average BC for the group. The random causes of BC error are not overwhelmed by the coning motion, so that the scatter in the BC measurements is about the same.

When the rifling twist rate is very slow for the bullet (e.g., the 1x12 twist rate in Figure 2.5-2), we believe that the coning motion increases dramatically. It certainly has a systematic effect on measured BC, and it also has a random round-to-round variation, which overwhelms the random errors associated with small variations the bullet shape or construction. In this situation, fired bullets are only marginally stable, and accuracy is usually very poor. When long, slender, heavy bullets are used in any caliber, fast rifling twist rates are necessary for good bullet ballistic performance and accuracy.

Figure 2.5-3 shows BC measurements made for Sierra’s 30 caliber (.308 inch diameter) 190 grain Hollow Point Boat Tail MatchKing bullet as a function of rifling twist rate. The twist rates in the test barrels varied from one turn in 8 inches (1x8) to one turn in 14 inches (1x14), except that we did not have a test barrel with a 1x13 twist rate. All BC measurements were made by the initial velocity and time of flight method. All rounds were fired at around 2350 fps using the 308 Winchester cartridge. Fifteen rounds were fired for each rifling twist rate.

Figure 2.5-3 shows the same characteristics for the 190 grain 30 caliber bullet as were observed in Figure 2.5-2 for the 69 grain 22 caliber bullet. The average BC values for the groups are relatively consistent for rifling twist rates from 1x8 through 1x11. The criteria for standard deviation and extreme spread are satisfied very well for these groups, and the scatter patterns are tight. The group for the 1x12 rifling twist rate has a lower average BC value, and with the exception of one “wild” round, the scatter pattern is tight. However, when the rifling twist rate is 1x14, a dramatic decrease in average BC value occurs, with a large increase in the scatter of the BC measurements. This bullet could be used in a barrel with a 1x14 twist rate only if it were fired at a considerably higher velocity to improve stability, such as in one of the 300 Magnum cartridge types.

Bullet coning motions usually tend to damp out as the bullet travels down-range. That is, the coning motion of a bullet is largest when it leaves the muzzle and grows smaller as the bullet flies downrange, basically because of air friction. Some shooters refer to this effect as the bullet “going to sleep,” and it can be observed in BC measurements. The effective BC of a bullet is often higher if the measured range between the initial and final chronographs (for the measurement method of Section 2.3.1) or between the initial chronograph and the time of flight screen (for the measurement method of Section 2.3.2) is closer to 200 yards rather than 50 or 100 yards.

[Larry Gibson]

Leftiye

Just in case the above post was too much for you let me put it in simple (that should work for you) terms. Sierra tests for bullet instability just the way I do. Actually they do it exactly as I do. They also use a 3 diget BC. Works for them, works for me and it should work for you...except.....oh yeah, you don't have a M43, never had one and don't have the slightest idea what you're talking about. If you don't like the way I'm testing or disbelieve the results then take it up with Sierra. Perhaps you will listen to them and learn something.

Larry Gibson

[leftiye]

Wow, what a bunch of hot wind. And you agreed with what I said? Bullets are stable when they don't yaw, tumble, corkscrew etc. and they are unstable to varying degrees when they do wobble etc. to varying degrees? Is that correct?

They (boolits) can yaw, corkscrew and etc for other reasons than Rpm effects? Yes?

If your definition defines those unstable, but not yet tumbling boolits as stable, then you can say that the inaccuracies that occur are because of rpms? Yes?

And now boolits do go to sleep? Oops, I guess that was Sierra saying that. So you were just messing with everybody and wasting our time about this back when McMillan was brought up?

If they don't show up in changes of B.C., then you have said that they are stable (by your faulty definition) yet here you say that all bullets wobble and yaw etc. to some degree. Also you say here that that contributes to inaccuracy. Inconsistent, Larry (I should leave out the comma).

Heck Larry, should I now copy whole sections of irrelevant material out of several books to pad my post so as to look as impressive as yours? Or is it sufficient to just ask the questions (or in your case answer them)? I don't see where you answered my questions Larry.

I only have to call Oehler to get a straight answer on what is the smallest period of time that will show up as a change of B.C on an Oehler 43. We both Know that. All the rest of that is nice, but it is irrelevant to what was asked.

Just to make it simple enough that you can understand this Larry (fair is fair after all?): I don't have any problem with how you are testing, at least as far as your chrony is concerned. But your test structure seems to contain a few fallacies.

[Larry Gibson]

Leftiye

Wow, what a bunch of hot wind. And you agreed with what I said? Bullets are stable when they don't yaw, tumble, corkscrew etc. and they are unstable to varying degrees when they do wobble etc. to varying degrees? Is that correct?

No that is not correct. I agree with the ballisticians at Sierra; "It is well known that bullet stability is critical for accuracy, but it is not well understood that there are different degrees of bullet stability." It is you that have an obsurd idea of bullet stability. You obviously lack the intelligence to comprehend what the Sierra ballisticians and I have been saying. There is a diiference between ignorant and stupid. Ignorant is not being able to understand, stupid is being able to understand but not. It has been presented to you numerous times by me that there are varying degrees of bullet stability. I have presented the same thing to you by Sierra ballisticians. All other ballisticians will present that information the same way. It is indeed not very well understood by many but you have had ample opportunity to understand, yet you do not. I do not believe you are ignorant.

They (boolits) can yaw, corkscrew and etc for other reasons than Rpm effects?
Yes?

That is correct and I've said it many, many times in this thread. An intelligent person would have noticed and understood that.

If your definition defines those unstable, but not yet tumbling boolits as stable, then you can say that the inaccuracies that occur are because of rpms? Yes?

As I've said, and you've failed to understand, the yaw, pitch and wobble cause inaccuracy and RPM affects the imbalances of the bullet causing further inaccuracy but that inaccuracy is in a linear fashion down range. With regular cast bullets non-linear inaccuracy is caused when the RPM overcomes the rotaional stability (whether it is also yawing, pitching or wobbling or not) at a certain level. That level is almost always within the RPM threshold of 125-140,000 RPM. An itelligent person understands what is being said. He may not agree but at least the intelligent person understands.

And now boolits do go to sleep? Oops, I guess that was Sierra saying that. So you were just messing with everybody and wasting our time about this back when McMillan was brought up?

My gawd but you do miscontrue everything. No one here doubts that the instability of yawing can and does smooth out over a distance from the muzzle. That is what is referred to as "the bullet going to sleep". It is exactly what many of us here have said. It is exactly what the Sierra ballisticians said. What is doubted is the claim that bullets, by going to sleep, will shoot smaller groups at farther range than the do at closer range, 100 and 200-300 yards to be specific. That is the point of contension here. An intelligent person understands that.

If they don't show up in changes of B.C., then you have said that they are stable (by your faulty definition) yet here you say that all bullets wobble and yaw etc. to some degree. Also you say here that that contributes to inaccuracy. Inconsistent, Larry (I should leave out the comma).

An intelligent person understands that if there is no change in the BC then the bullet remains as stable as it was. An intelligent person (seems to be me, everyone else here and the Sierra ballisticians. Every one but you) also understand that if the same bullet has a lower BC when fired at the same velocity it is not as stable.

Heck Larry, should I now copy whole sections of irrelevant material out of several books to pad my post so as to look as impressive as yours? Or is it sufficient to just ask the questions (or in your case answer them)? I don't see where you answered my questions Larry.

An *********t person sees and understands where I've answered your questions.

I only have to call Oehler to get a straight answer on what is the smallest period of time that will show up as a change of B.C on an Oehler 43. We both Know that. All the rest of that is nice, but it is irrelevant to what was asked.

So why don't you call Oehler. Dr. Oehler is a very nice gentleman. I have discussed this numerous time with him. You might learn something from him but then since you don't learn from anything else that is doubtful. Be sure to tell him how you not only disagree with me but the Sierra ballistians and how what they say is "hot air". I'm sure he'll appreciate that line of intelligent thinking.

Just to make it simple enough that you can understand this Larry (fair is fair after all?): I don't have any problem with how you are testing, at least as far as your chrony is concerned. But your test structure seems to contain a few fallacies.[/QUOTE]

This has absolutely nothing to do with "fair". It has to do with facts. An intelligent person understands that, obviously a simple or stupid person doesn't.

You say you have "no problem with how you are testing" and then in the same sentence say; "your test structure seems to contain a few fallacies". An intelligent person sees the inconsistancy and contradiction of that.

The real questions here, since you not only won't, don't or refuse to understand what is being said are; are you intelligent or stupid and why do you continue to waste our time with such stupidity?

Larry Gibson

[Larry Gibson]

If this thread could get locked it would be fine with me.

Larry Gibson

[45 2.1]

If this thread could get locked it would be fine with me.

Larry Gibson


Not everybody agrees with you or your conclusions, nor does jacketed ballistics always apply to lead boolit ballistics. You also do not always answer inconvenient questions either.

[pdawg_shooter]

I was told if you protect your cast bullet with a bit of paper then jacketed ballistics DO apply. Dont know why, but the master told me so.

[BABore]

If this thread could get locked it would be fine with me.

Larry Gibson


And very convenient for you too!

[leftiye]

I will only respond to the reference to the Sierra quote. I won't ask you again if you can read, or comprehend what is there for all to see.

"It is well known that bullet stability is critical for accuracy, but it is not well understood that there are different degrees of bullet stability."

Isn't this the same as saying that there are degrees of instability? Isn't it just another way of saying what I have said? Isn't it Just the inverse of my statement?


I notice that you now agree with me in several areas where previously you would have preferred death to any accomodation. Does this mean that all of this hasn't been a waste of time after all?

As for the rest - Just re-iterating your opinion hasn't ever proven anything (Remember, those opinions were never proven). As in never. Nor has ICM.

[leftiye]

[What is doubted is the claim that bullets, by going to sleep, will shoot smaller groups at farther range than the do at closer range] L.G.

Didn't they (Sierra) also say that the conical presession was from a larger spiral near to the muzzle to the point where the boolit became stable? So it's not possible that the spiral is in excess of 1 moa, and that the stable bullet group is less (say 1/2 moa) than that? Didn't McMillan's groups go from being uniformly 1 1/2 moa at 100 yds to being in some cases 1/2 moa at 2,3,4,5, and 6 hundred yards? Isn't a 1/2 moa group 1" at 200 yards?

Just a point of interest, If those spirals were 1 1/2 inches at 100 yds, how big would it be reasonable to think they were earlier - nearer to the muzzle? Say, maybe 2" at 50 yds?

[Bass Ackward]

If this thread could get locked it would be fine with me.

Larry Gibson


I don't think anyone has this 100% understood. If they did, then we could be told what bore diameter is superior, what bullet shape is clearly superior, and then what exact twist rate we would need to deliver a superior bullet outta that superior bore to "X" distance etc.

Many military organizations have studied this time and time again using the most sophisticated equipment on earth and everyone comes up with different answers. Kinda like us! :grin: The fact that this has never been settled tells me that the world is full of dummies with their heads up their butt, just as bad as we are. We just simply go one step farther by using a softer bullet to try and complicate the matter. So I don't feel too badly with what I have available and what I manage to accomplish.

[Bass Ackward]

Try this for low and high RPM flight:

A child's toy, the top, spins and wobbles twice, once when over-spun and once when it is no longer spinning sufficiently to maintain it's balance. The maximum RPM of this top will vary from person to person. I could always get the top to rotate smoothly at a higher RPM than my cousin could because of how I applied the force. So how smoothly the force or the pressure applied and the release means everything to what top RPM was achievable.

As the force required to spin it faster increases, fewer and fewer methods (loads) were acceptable to achieve good rotation without experiencing and increasing high end wobble at lower RPMs. The force also effects the low RPM level as to how low it can go without falling over. So force and a good launch are critical to high and low stability. If your applied force or the rate the force is applied changes the rotational stability of your top for the negative, regardless of the level, then it is logical to assume that the wobble from the high and low end points are going to lower on the high side and raise on the low side. The operator of the top has control on the dramatic effect on HIS RPM limits and why some can, and some can't.

Question is how do we do this as it pertains to cast? 1. is to establish good alignment so that balance during rotation is achieved. 2. apply force slower and longer to any slug. 3. Use a harder slug when possible. And 4. using a lighter slug so that it can overcome inertia faster and in essence be the same as 2. Steps 1, 2 and 4 are where most reloaders lower their top end ceilings regardless of their twist rates which lowers the amount of acceptable loads that are smooth enough to produce acceptable / stable launches. Learning what variables are involved and how to improve these steps, affects the final RPM number and are keys to reloading for high RPM.

Now can we design a better top? Oh yea. If the weight is on the peak of the top, (front of the bullet)that top is going to become less stable sooner on both extremes. It will be effected more because as it starts to destabilize, momentum from this movement at the peak or front, will move the slug earlier and farther and as RPM increases, causing it to catch more head wind and amplify the effect. The opposite occurs when weight is at the bottom of the top. (base of the bullet) The one with the weight on the bottom will still wobble, just the lighter top weight will make it have less momentum effect from rotational stability. IF it wobbles less, it catches less wind, and and it has less force to move it off target. Or it can go faster!

The weight on the back of the slug will therefore make applying the force to the slug "less critical" too, than if the balance point is farther forward. Even if the high end rotation limit is not increased, you will be able to achieve higher rates of balanced rotation with a wider load selection. It also lowers the destabilizing low end rotational point so lower velocity can be achieved accurately.

Semi wadcutters, for handguns, and bore rides, as they are called when they are put in rifles, are cast examples of this. Spitzer and hollow point designs are also examples of this principal if they can be adapted to cast. The critical point is that bearing area remain long enough so that central alignment in the bore can be maintained when encountering rotational forces and fouling up the pipe. Removing nose weight (improving BC) and lengthening the bearing area, without increasing overall bullet weight are helpful to steps 1,2, and 4. above. Those actions minimize the critically of step three which is hardness that is fairly limited considering a lead top. If we are going to allow our slug to collapse, the resulting slug shape and balance must be considered for overall rotational effect both high and low. In the middle RPMs you have a wide margin for error and less head wind to cause problems so "perfect rotational stability, is less critical to final accuracy.

Since the quality of your top is set from your top mold and you have limited ability to alter it with factory tops, going harder is about your easiest option to allow you to perform steps 1,2, and 4 better to go higher. Learning how to improve steps 1 through 4 better will make the difference in how difficult it is for you to spin your top properly without seeing it destabilize and fall to the floor at some lame RPM level. The more wind force that hits your top during forward movement is going to increase the destabilizing force or lower the top's RPM ceiling. So the faster it travels, the fewer good / smooth launches will be acceptable and the more vulnerable it will be to ALL forces including head wind.

Moral of the story is don't over spin OR under spin your top or go faster than necesary if you can't figure out how to control steps 1 through 4. If you don't understand or learn, regardless of exactly what force is working against you, your crime is misunderstanding. Your penalty will be to be limited by RPMs on both ends of the spectrum and you will be sentenced to believe in the RPM effect for life. :grin:

[carpetman]

Now we have kids tops in the thread. How many of you know how to spin a top with a string wound around it? I think this is becoming a lost art.

[runfiverun]

bass think a 100gr boolit would work here?
in the 308 10 twist.

[leftiye]

R5R, Even an idiot like me can make that go 2400 fps. out of my 30-30 contender. The 311359 seemed to be accurate - though back then I only sighted in on running rackjabbits. Was a whole lot more fun to shoot than the 180 gr. Loverin boolit.

[Larry Gibson]

Alright, alright you all win ok....now you all can go on doing what you have always done. I really don't care. After all you are the resident experts here and anything else anyone comes up with is ridiculed. I will continue the test in spite of your continued ignorance. The results will speak for themself. That make you all happy.

Probably not as I will continue to tell anyone who asks why they can't get any accuracy with their cast bullets above a certain velocity level what the real reason is.

Those who may care. I will not post any more results of my RPM tests in this forum. For those of you who have PM'd me with all the support in the world I say thank you. Unfortunately you have let these four individual continue the ridicule unabated. I have wasted enough time with them. It would have been much better for the PMs to have been made openly on this forum. However your silence has only given strength to ignorance. I will not put myself through another thread with these individuals to just ask assininee questions and come up with examples that are not pertinant to the question (Carpetman and runfiverun exluded). You all can read, I have answered their questions over and over and yet they keep bring the same questions up. I really don't care, and have stated such over and over again, if they disagree. That is fine but at least they could be intelligent enough to present evidence that is pertinant. The top spinning is a good example. Bass should try that with an unbalanced top. Bullets are unbalanced you know but he doesn't. He contines with the same old drival in the face of test evidence. He ask me to conduct a test say that would prove RPM was the cause. I did and it proved it but he has now reegged. I'm am tired of this ignorance of facts and belief in witchcraft an voodoo.

I will post a brief synopsis of what future tests are about but will not post any of the results on this forum. If anyone desires to advance their knowledge they may PM me for the test results.

Leftiye, you are free to get the last word in, you always do anyway.

Larry Gibson

[EDG]

Larry and EGD

Big thing I see with website EGD post is all powders extremely fast ones. We all know that all those calibers get good accuracy with more slow rifle powders and at much higher velocity then what site had. Interesting website and information yes prove anything to rpm thresh hold here...no.

Ralf

Tiger,
The observations I made were 2 or 3 years ago long before this thread started. If you will notice in a number of the calibers the groups grow radically at about the same velocity. Mere coincidence? I think not. Burn rate of the powders are fast but if you compare similar burn rate to a similar burn rate I think it tends to cancel out.
BTW What do you think limits cast bullets?

[Tiger]

Tiger,
The observations I made were 2 or 3 years ago long before this thread started. If you will notice in a number of the calibers the groups grow radically at about the same velocity. Mere coincidence? I think not. Burn rate of the powders are fast but if you compare similar burn rate to a similar burn rate I think it tends to cancel out.
BTW What do you think limits cast bullets?


Hello EDG

Yes I notice the charts. I know that all those calibers can be made to shoot high velocity with accuracy with slower rifle powders too. There is big performance difference between fast pistol powders and slower rifle primers.

From my observations beginning to think one of major obstactical limiting the cast bullets shooting you ask of is knowledge of the cast shooter. Like I say many times it can be done but no so easy by unexperienced.

Ralf

[Bass Ackward]

Bass should try that with an unbalanced top. Bullets are unbalanced you know but he doesn't. He contines with the same old drival in the face of test evidence. Larry Gibson


Larry,

The top was one of those hollow metal ones painted like a Merry Go Round. It was about 14" high and about 12" in diameter. It had the cork screwed metal shaft (twist rate) with a wooden handle on it. You pulled it up free, then pushed down to increase the RPMs. How you pumped that top and released that handle made all the difference in the world what RPM level you could reach and how long it would spin.

That thing WAS outta balance worse than ANY bullet. IF it wasn't when it was new, it sure was after we kids bent the hell out of it. And no matter what condition it was in, there was still a difference in the maximum RPM that different people could achieve out of that top. Dented or not dented.

Your statement above, as you chide me, is clear proof, along with everything else in this thread that you believe RPMs is an absolute, contrary to past claims that you have shot HV accurately. Once or twice in this same thread.

This causes confusion. Is accuracy at high velocity possible or not? Would you please close out this thread by giving us a summation of what YOU think your test has really proven and answer that question? Although I believe your quote at the top of the page says it all.

[Larry Gibson]

Bass

I will answer your question but first please let me vent.

Obviously no one reads what I post (except the Honcho;-)). First of all the test is not complete. I said at the get go I would not make any conclusions until the end. I have tried to stick to that but you and others have made it impossible. I do believe I have already answered that question numerous times in this thread already, contrary to the statements of others. I have answered; they do not like the answer so they continuously say I'm either not answering or avoiding the questions. There have been a few derogatory comments referred/inferred about me because of their beliefs. I will not re-engage those individuals in further discussion regardless of what they say. If they want the answer all they have to do is read the thread again. They do not have to agree with my answer but at least they should read the answer. As the test is not complete I feel it is totally unfair to ask me for a conclusion to the question I am testing for when it's not complete.

Also quite bluntly I have told you and everyone else that I am through with this thread. Yet you all keep coming back with the same inane questions that simply could be answered by reading the thread (at least the part pertaining to the test). However I will answer your question this time. Be warned however that my answer to your question here is final. I will not further discuss this matter on this thread. That should be perfectly clear to every one.

To answer this question; "Is accuracy at high velocity possible or not". As I have stated numerous times (even giving you credit with doing it with your LBT bullet) the answer is ; YES.

However there are two caveats:

First; accuracy at HV (2500 fps) will not happen with a regular cast bullet in a 10 or 12” twist barrel. With a specially designed bullet such as your LBT bullet, or possibly one like 311466, that fits a specific cartridge and chamber throat "accuracy" is possible as I have already stated numerous times in this thread. Also specific casting and loading techniques are required with such a bullet when loaded at HV so that "accuracy" is reproducible under a variety of conditions.

Second is that the best "accuracy" with that bullet will still be in or below the RPM threshold.

The test thus far has proven that a regular cast bullets, in this case 311291, accuracy is adversely affected by the effects of RPM when pushed above a certain level within the RPM threshold. The exact point within that threshold where the bullets accuracy is adversely affected is dependant on many of the things we already understand; quality of casting, lube, alloy hardness, barrel uniformity and quality, etc. At some point within the RPM threshold, based on those things we already understand that effect accuracy, the centrifugal force over comes the rotational stability and increased inaccuracy occurs in a non-linear fashion. This is not to say that the RPM causes the bullet to become unstable(r). This is proven because the BCs of the three twists stays the same at the same velocity and the same pressure with the same load out of the three different twists. Since the BC stays relatively the same it tells us that the rate of twist is not causing further deformation of the bullet with the faster twists. Contrary to what has been posted the M43 is quite capable of measuring the subtle change in BC that would take place if the bullet of the fast twist suffered greater deformation or instability. These are accurate rifles with proven accuracy during the test. This negates any consideration of bad crowns or bad launches. The test demonstrates that with pressure eliminated as a cause of the inaccuracy, and with velocity eliminated as the cause then that narrows it down to the last thing that causes the inaccuracy. That is RPM. As the bullets was pushed into and through the RPM threshold with all three twists the 10" twist barrel gave proportionally worse accuracy than the 12 and 14" twists. The 10 and 12" twists gave proportionally worse accuracy than the 14" twist. This will velocity and pressure equal among the twists. All of this is well documented on the graphs and is quite obvious.

However, that is the results of the first test. I yet have to conduct the same test with the 311466 in all three twists. I also have yet to test numerous other regular cast bullets in these 3 twist rifles with the M43 to see how those bullets fair when pushed into and through the RPM threshold. I will test 311041, 30-150-FN in all three twists. I also have yet to test the following cartridges with regular cast bullet pushing them into and through the RPM threshold to HV (2500 fps) recording the same data with the M43. I will test the 6.5 Swede, the 7x57, the 30-30, the 30-06, the .303, the 7.62x54R, the 7.65 Argentine and the 8x57. The conduct of all these tests may or may not verify the RPM threshold. I will then work with th311466 in either the .308 with 10" twist or the 30-06 with 10" twist testing one individual variation of alloy hardness, sizing, lubes, AOL, powders, primers, "nodes", etc. to determine what actually may improve accuracy at high velocity (2400-2500 fps).

The test is not complete. As I’ve said numerous times in this thread I may prove all of this RPM threshold theory wrong. If I do I will be the first to admit it. However as of the results of the first test that is unlikely as the evidence strongly points to the existence of the RPM threshold.

That is my answer, take it or leave it.

Larry Gibson

[Tiger]

Larry,

I done shooting to more or less test some bullet lubes. One lube was famous 50/50 alox/beeswax. Other lube mixture of alox and special synthetic oil. The rifle I use is 98 mauser with new barrel in 6.5x47 lapua. It has 8 rifling twist. A friend with me worked up load from powder from old German 8x57 cartridges. By way we not as fortunate to have surplus powder as you. We wish but no. Velocity was 2002 fps which give 180180 rpm if I am correct. This out of your threshold. First target is 20 shots with 4 different load but with 50/50 lube. You will not count that many holes because some bullets in same hole as other. The next target is just 10 shots with other lube I tell about. One can see big difference. The round circle part target is 53 millimeters I think just over 2 inches. First time cast in 6.5x47 lapua barrel but it was shot with jacket bullet to wear in first. Not at same time. This was done before today shooting.
I just wanted to show how small thing like lube can change things big. I believe Bass is very smart about this too.

Ralf


http://i285.photobucket.com/albums/ll42/Ralftiger/scan0002.jpg

http://i285.photobucket.com/albums/ll42/Ralftiger/scan0004.jpg

First time try this picture site to post here. I think little more work and different powder and this rifle shoot and high rpm too.

[Larry Gibson]

Ralf

Assuming 100 meters? In the first picture can you mark the shots of the " 4 different load" and give us the load/veocity of each? Also what was the load/velocity of the 10 Shot group?

I used to shoot a lot of the old German surplus 8x57 and found the powder used to be of comparable burning rate with 4895. German stuff is not available but I've been shooting a lot of the Equadoran and Turk stuff. I think they used German powder. Good stuff and I reduce the load in the Turk ammo to ease extraction. About 10% of the necks split when the bullets are pulled. I used the surplus powder to load other 8mm bullets in commercial cases. A friend pulls down a lot of Turk ammo and gives me the primed cases. I use them with PB cast bullets over Bullseye for 100 fps plinking loads. They are great for a walk about rabbit load.

Larry Gibson

[Tiger]

Larry

I apologize yesterday I forget some things. I have a friend who is excellent machinist. I say this because we make molds together. The bullet I am using is copy almost directly Saeco 140 grain. Ok 4 different loads mean different lubes different bullet seating different primer and same powder. I shoot test loads to get velocity and answer your question all velocities 2002 fps. Major difference I see I mention before is fouling. In my case fouling bad boy for high rpm.

Okay out today again. This time some adjustmet to powder. Velocity now 2050 fps. That give 184500 rpm. Except for flyer main group 13 millimeter. 5/8 inch ?

I thing you agree 184500 out of you threshold. Alloy for bullet still not so hard. It is wheel weight with pure lead. I use annealed gas check. Bullets are water hardened.


Ralf

http://i285.photobucket.com/albums/ll42/Ralftiger/65Germany.jpg

[Bass Ackward]

Ralf,

Nice shooting and a nice cartridge, but still fairly small for what you are trying to do at HV with cast. I would get that machinist buddy of yours to cut you a one diameter 100 grain bullet mold and watch what happens. Plus you may need a little slower powder still.

I tried that bore diameter with a 100 grain bullet in a 6.5 - 06 with a 9 twist. I got 1 1/2" groups and less using just ACWW at 2600 fps. That's 208,000 and change.

Then find out if that flier is a fouling flier. :grin: That barrel may need more break-in. :grin:

[Larry Gibson]

Ralf

Without being politically correct I'm going to tell you what I see; the first two targets are 6 moa or so (still assuming 100 meters?). With the first target you were changing things with the load. Without knowing which bullets hit where the overall grouping means nothing and tells us nothing except you shot a 6+ moa 20 shot group.

The second group is also a 6+ moa group. Assuming a good rest and a good accurate scoped rifle that may be ok to some but to me it is pretty bad.

As to the last group; one 5 shot group in which 4 shots are "good' and there is one flyer (making group around 2 MOA). Was the flyer called? I would suspect that load isn't really any better than the previous ones. This is because the next shot(s) may very well be flyers even farther out. Shoot 3-5 more 5 shot groups and if they are ALL like that 4 shot 5/8" group then you may have something. However with that bullet design I doubt you will get consistant 5/8" or even 2 moa or under accuracy at that velocity/RPM level.

All your loads are well out side and above the RPM threshold. Accuracy is poor, RPM is the reason. Drop your load back so the velocity is in the 1400 - 1600 fps range and show us some groups. Otherwise if you want to push thevelocity up to 2000 fps then get the smaller mould as Bass suggests.


Larry Gibson

[Johnw...ski]

This is just my observation, but it seems to me that the optimal RPM range is diameter specific. What will be the maximum RPM for .30 cal. is going to be more than the maximum RPM for .45 cal. due to centrifical force.

Some of you may have seen some of my threads on my trials and tribulations with my 14" twist 45-70, I am now working with my .35 Whelen in an identical action with an identical scope, the same length and contour barrel with 14" twist and am getting MOA accuracy at what should be slightly higher velocities than the best 45-70 loads. It doesn't matter weather the boolits are 245 gr. or 290 gr. or what the load is this .35 shoots well. The 45-70 on the other hand was very load specific and still couldn't match the .35's accuracy with the best loads. The
45-70 is out being rebarreled now and will come back with an 18" twist, time will tell how that effects accuracy.

I do see the merit of investegating the RPM ranges but have come to realize it is a range for a specific diameter, increase or decrease the diameter and the range will decrease or increase respectively.

John

[runfiverun]

i think john
is on to something i have thought this and am going to start working on it when
my g/c's for my 7mm get here.
for some reason i also think the outer hardness of the boolit has an awful lot to do
with this also..

[Larry Gibson]

I really don't think the effects of RPM on accuracy are all caliber dependant. I've shot a lot of cast bullets over the years in cartridges from 22 Hornet up through the .458 with 14" twist. I've consistantly found accuracy to go south when the bullet enters the RPM threshold with all cartridges up through the .375 H&H with twists of 12" or faster. The problem with accuracy I had, along with others, is that recoil is substantial with bullets of 350 gr or more when one gets into the 2000 fps range. With a 14" twist the bullet doesn't really enter the RPM threshold until 2400+ fps is reached. That is a lot of recoil to handle when shooting groups off a bench. Perhaps the use of a Lead Sled would help. I have shot the RCBS 300 gr GC bullet at 2400 fps with quite good accuracy at 2400+ fps out of my Siamese Mauser 450-400-70 but it has a 22' twist and only is cranking 78,500 or so RPM. I recently aquired a mould for that bullet and at sometime will get around to testing bullets out of that mould in the Mauser.

I also will test a considerable number of calibers from .223 up through the .375 as part of the RPM test. We will then have test data to compare the difference. Let us not forget that the threshold is for the most part from 125-140,000 RPM. That leeway accounts for variances in alloy, bullet design/fit, accelleration, etc.

Larry Gibson

[Tiger]

Larry,

I have other target for you. Same rifle 6.5x47 same load except brass change. Also ten shot group. Interesting thing first shot clean barrel in main group. The outside shot I mark number 9. I make mistake on this shot. All ten shots first to last.

Larry you will not admit you are wrong. First you tell me post targets I do. Yes you will say not enough proof. Even Bass give you proof. You have nothing but excuses. Upon your further tests one thing still bother me about them. That is you are doing them. Until you can get group of accomplished shooters together to run test your tests mean nothing. There are among us here some that can shoot high velocity but you deny.

Runfiverun I sorry to say you change ideas more then automobile designer. This mean to me you are guessing.

Larry I post all my targets just not good ones.

Ralf

http://i285.photobucket.com/albums/ll42/Ralftiger/65x47.jpg

[runfiverun]

tiger
i am not really changing ideas.
i am actually trying to put the whole picture together, as i am working on several
projects at once [308 lube type test] 45 colt p/b vs g/c velocity,leading. 30-40 krag
slow velocity flat line test.
plus military match shooting, lever action silhouette. and hand gun hunting high vel loads.
nevermind the long range silhouette shooting.

it is not so much changing my mind as pointing out some observations i have made
i have never taken a side in this arguement as all the facts are not in
all i have ever done is point out the facts as i have seen them
especialy the ones where you guys have slammed larry for sticking to his tests
and pointing out what his observations have been.

i actually think larry is on to something here, it just needs to be refined for each caliber and he will as he goes along.

that is a pretty good group there do you have to clean after every few shots?

[Bass Ackward]

Ralf,

I suspect that flier is resulting from a pressure change and you are operating on the edge of your lube. As this happens, I go with slower powders to minimise ignition effect changes.

Have you tried pistol primers? With the less friction of lead over copper, you can actually see a hot primer. Pistol primers are slightly cooler and statistically more uniform. Might make all the difference for you. If you try them, you might have to alter your powder charge one way or the other, maybe not.

[Larry Gibson]

Ralf

I'm not going to get into another long winded discussion with you. It is fine that you post targets. However you post a target with 4 things changed in, we asume, 5 shot strings. You fail to mark which groups are which in that 20 shot group. The group size is over 6 moa, still ASSUMING 100 meters,. Just how do you expect any observation made on that except "pretty good shooting" which it really isn't.

I will not admit I'm wrong because you nor anyone else hasn't proven I am with actual comparative tests. The tests I conducted demonstrate that I am correct. What exactly does your test mean? Ok, you are shooting 2+ moa groups (still ASSUMING you are shooting at 100 meters) at 2000 fps and 180,000+ RPM. Golly gee whiz but when have I ever said we couldn't get ok accuracy above the RPM threshold. When Have I ever said that accuracy always went radically bad when over the RPM Threshold? Isn't it a fact that I've always said that accuracy gets proportionately worse with faster twists? What I have always said was that best accuracy will be below or in the RPM threshold. So why don't you drop the velocity to 1400-1600 fps and see how really well your rifle does shoot? It is only then that we will have a meaningfull comparison of accuracy to make. Until then, yup that last target is 2+ moa excluding your called flier.

Sorry but your targets prove nothing. To be meaningful you need to seperate out a single change to one test. Then we may see the difference that test made. However one still needs to have something to make comparison with. Your last target is a 2+ moa group. But is it good or bad compared to what accuracy that rifle is capable of with that bullet. You won't know unless you work up through various velocity levels and then have a basis for comparison. Right now that's just an ok 2+ moa group as I've already said. The question is; can you get better accuracy in or below the RPM threshold. You haven't answered that. Right now you are only guessing. If you want to conduct a test that is meaningfull and may demonstrate something pertinant to the RPM threshold test shoot 10 shot groups at 1400 fps, 1500 fps , 1600 fps, 1700 fps, 1800 fps, 1900 fps, 2000 fps, 2100 fps and 2200 fps. Keep all componants the same except increasing powder charge. Clean the barrel between groups. Then chart the groups out on a graph comparing velocity to group size. Then chart the groups out on a graph comparing RPM to group size. Come back with those results thus cahrted and we shall talk. That is a test. Your last "test" is just a 2+ moa group excluding the flier and a 3+ moa group including the flyer.

Also, some don't consider 2000 fps as "high velocity". Why don't you push your bullets up to 2500 fps and see what happens.

I could really care less whether or not you think I'm an "accomplished shooter". I'll also bet money any group of them is going to find the same thing I am finding out. Actually you are finding that out with your test but just don't realise that fact. Come back with the above mentioned test and you will have proven it yourself so every one else can see.

Larry Gibson

[Bass Ackward]

Larry,

See if I can shed some light here. This is your key statement that is not always understood clearly as you argue in absolutes.

<<What I have always said was that best accuracy will be below or in the RPM threshold.>>

I even miss that when you are .... discussing "your test". And Ralf is translating. What confuses us is statements like, "All cast bullets always being outta balance." then says to me you believe that high RPM accuracy is impossible. And we know this is untrue.

On a side note: I do think Ralf's test has some merit here. He is turning some RPM without fighting the head wind of higher velocity. RPMs is RPMs. If he tweaks that in, then there has to be other forces at work besides RPM. And this was one thing you were trying to determine, is all inaccuracy a factor of RPM? Yes? If I still understand, I think you were basically saying that RPM was responsible for 100% of inaccuracy as neither pressure nor head wind had any effect. RPMs without velocity is one way to .... minimize ballistic coefficient and air effects although pressure is still present.

I see now what our main difference has become. Back to your key statement, I look at a load as accurate or not. Velocity level is unrelated to my thought process. Type of gun is immaterial. I look at what steps that I have to take to obtain that accuracy, then make my decision if it is a load worth using or not.

My accuracy standard is defined by others instead of the gun. I determine accuracy by what others achieve with their best efforts regardless of the velocity level. I have several HV accuracy loads that not only meet my criteria for accuracy, but they beat the best efforts of others at low RPMs.

After a few years on this board, it seems that the accuracy standard for just about everything is 2" to be considered as good cast bullet accuracy. Military guys say that they are competitive with 2" and I understand this is open sights. Levers is 2". Scoped guys get happy as they approach 1 1/2" with anything. Even at the cast bullet benchrest matches, 1" groups will not have you come in last place as you look through the data. And believe it or not, I even see jacketed guys that are happy using these figures. 1 1/2" is a fairly good standard for "sporting arms". And nobody mentions velocity levels. It is what it is, accurate or not.

If I go to jacketed, my results will be good groups at first and then things open. If I start with a HV load, I might get two groups sub MOA and then the next ten be 1 to 1 1/2". IF I keep firing that rifle, groups will eventually open up to 2" with any load. I develop the RPM syndrome. I regularly received customer guns that shot 4" with copper for rebarreling. Clean these and they went back sub MOA. If you shoot low velocity jacketed so that fouling is minimized, you will have better accuracy for longer strings. And you have less change from heat and harmonics too. So "best accuracy" as you call it is the same for jacketed then.

My point is that you can take the most accurate gun in the world and run 100,000 rounds through it and have it shoot 6" groups eventually. From this you can say, all rifles regardless of caliber or quality shoot no better than 6" groups. No rifle is more accurate than another. This is extreme, but the same logic really. So someone that wants a 10 shot group gets one really good group from me. If they require 20 shots, then I am just OK. If they want 2 separate 20 shot groups with copper to determine if I am accurate, I'm screwed. If you shoot something or abuse something long enough, you can make anything inaccurate. Fouling affects everything, cast and jacketed, and it gets worse the more you go up. Lube is fouling. Fouling alters harmonics and pressure, everything. So I can eventually have RPM syndrome with jacketed. Which is why the military tones down loads to get longer accurate shot strings between cleanings across many guns. They have different standards fgor jacket material too, but that is a different issue. But we only have to deal with one as reloaders and we can clean when we want and we can alter bedding to perform where we want to.

So to simply say that if I confine myself to one powder and one lube, I will see things get worse as I go up is not how the game is played with anything in the shooting world, little alone cast. Cast is the KING of changes. And the advanced course for shooting. We reload to be able to change variables when they require changing. And this affects our mind set. You can take a handgun and when you pass the metal hardness for that gun / load groups will start to open and continue to open even though RPMs are still way below rifle RPMS. Same thing.

And this is where I think Ralf is seeing things differently. Now I understand that you aren't going to agree with this. And that's OK. But you must understand how we define accuracy to understand how we argue our points. For us, the best accuracy is determined by load " A " compared to what we get with load " B ". Not whether load A is all it can be. And if load " A " generates this without RPMs, then it ain't RPMs that is limiting other loads. IT can't be, cause all our cast are outta balance right? That is where I think Ralf and others are losing you as they discount fouling and many other things that RPMs alone hides.

So is best accuracy in the RPM zone? By your definition .... yes. You can use dog do do for lube at that level and get good accuracy. You can mold crappy bullets. You can do many things poorly and still get accuracy. Is THAT your best accuracy for that rifle? Well until you shoot every combination out there, how do you know? Probably not. But if you start up the velocity ladder with dog do do for lube, you will go inaccurate long before me. Is that RPMs? . Now when it does, you are launching a bad .... bullet .... badly. So the slower you turn it from twist rate, the more accurate it is going to look. But the slower you turn it in the barrel, the less bad the bullet will be too and the less requirements on lube and hardness and rifling height too. Launch better bullets than someone else and you will have a higher RPM and velocity level. But it is still a bad launch that can be made better if you change your choices as Bob says.

That is the RPM syndrome. Don't change anything, and you are screwed as you go up. Happens with cast or jacketed eventually. Each individual makes the call. What people seldom realize is the their low velocity efforts can be improved also if you just understood and knew what to correct. That's what HV teaches is how to alter things for better results no matter what the velocity level. So "the zone" is the "easiest accuracy", not "best accuracy" from our point of view.

RPM syndrome is really an equipment and a reloader failure index. You can be the best reloader in the world with poor equipment and get good results in the zone. You can be a crappy reloader with good equipment and perform well there too. But it takes everything to put it all together as you move up. When you do, you can turn some high numbers. But clearly high velocity with the lowest RPMs has a broader spectrum. That still doesn't make it RPMs. Best accuracy occurs just before leading begins. Problem is the gas check doesn't let you see that point as it takes it out with it to hide the evidence. :grin: So at that point it becomes balance and RPMs. :grin:

[BABore]

Jeeze Bass, you must love typing. I said the same thing a few hundred posts ago with just four words, "Crap In, Crap Out".

[45 2.1]

Larry,

See if I can shed some light here. This is your key statement that is not always understood clearly as you argue in absolutes.

<<What I have always said was that best accuracy will be below or in the RPM threshold.>>

I even miss that when you are .... discussing "your test". And Ralf is translating. What confuses us is statements like, "All cast bullets always being outta balance." then says to me you believe that high RPM accuracy is impossible. And we know this is untrue.

On a side note: I do think Ralf's test has some merit here. He is turning some RPM without fighting the head wind of higher velocity. RPMs is RPMs. If he tweaks that in, then there has to be other forces at work besides RPM. And this was one thing you were trying to determine, is all inaccuracy a factor of RPM? Yes? If I still understand, I think you were basically saying that RPM was responsible for 100% of inaccuracy as neither pressure nor head wind had any effect. RPMs without velocity is one way to .... minimize ballistic coefficient and air effects although pressure is still present.

I see now what our main difference has become. Back to your key statement, I look at a load as accurate or not. Velocity level is unrelated to my thought process. Type of gun is immaterial. I look at what steps that I have to take to obtain that accuracy, then make my decision if it is a load worth using or not.

My accuracy standard is defined by others instead of the gun. I determine accuracy by what others achieve with their best efforts regardless of the velocity level. I have several HV accuracy loads that not only meet my criteria for accuracy, but they beat the best efforts of others at low RPMs.

After a few years on this board, it seems that the accuracy standard for just about everything is 2" to be considered as good cast bullet accuracy. Military guys say that they are competitive with 2" and I understand this is open sights. Levers is 2". Scoped guys get happy as they approach 1 1/2" with anything. Even at the cast bullet benchrest matches, 1" groups will not have you come in last place as you look through the data. And believe it or not, I even see jacketed guys that are happy using these figures. 1 1/2" is a fairly good standard for "sporting arms". And nobody mentions velocity levels. It is what it is, accurate or not.

If I go to jacketed, my results will be good groups at first and then things open. If I start with a HV load, I might get two groups sub MOA and then the next ten be 1 to 1 1/2". IF I keep firing that rifle, groups will eventually open up to 2" with any load. I develop the RPM syndrome. I regularly received customer guns that shot 4" with copper for rebarreling. Clean these and they went back sub MOA. If you shoot low velocity jacketed so that fouling is minimized, you will have better accuracy for longer strings. And you have less change from heat and harmonics too. So "best accuracy" as you call it is the same for jacketed then.

My point is that you can take the most accurate gun in the world and run 100,000 rounds through it and have it shoot 6" groups eventually. From this you can say, all rifles regardless of caliber or quality shoot no better than 6" groups. No rifle is more accurate than another. This is extreme, but the same logic really. So someone that wants a 10 shot group gets one really good group from me. If they require 20 shots, then I am just OK. If they want 2 separate 20 shot groups with copper to determine if I am accurate, I'm screwed. If you shoot something or abuse something long enough, you can make anything inaccurate. Fouling affects everything, cast and jacketed, and it gets worse the more you go up. Lube is fouling. Fouling alters harmonics and pressure, everything. So I can eventually have RPM syndrome with jacketed. Which is why the military tones down loads to get longer accurate shot strings between cleanings across many guns. They have different standards fgor jacket material too, but that is a different issue. But we only have to deal with one as reloaders and we can clean when we want and we can alter bedding to perform where we want to.

So to simply say that if I confine myself to one powder and one lube, I will see things get worse as I go up is not how the game is played with anything in the shooting world, little alone cast. Cast is the KING of changes. And the advanced course for shooting. We reload to be able to change variables when they require changing. And this affects our mind set. You can take a handgun and when you pass the metal hardness for that gun / load groups will start to open and continue to open even though RPMs are still way below rifle RPMS. Same thing.

And this is where I think Ralf is seeing things differently. Now I understand that you aren't going to agree with this. And that's OK. But you must understand how we define accuracy to understand how we argue our points. For us, the best accuracy is determined by load " A " compared to what we get with load " B ". Not whether load A is all it can be. And if load " A " generates this without RPMs, then it ain't RPMs that is limiting other loads. IT can't be, cause all our cast are outta balance right? That is where I think Ralf and others are losing you as they discount fouling and many other things that RPMs alone hides.

So is best accuracy in the RPM zone? By your definition .... yes. You can use dog do do for lube at that level and get good accuracy. You can mold crappy bullets. You can do many things poorly and still get accuracy. Is THAT your best accuracy for that rifle? Well until you shoot every combination out there, how do you know? Probably not. But if you start up the velocity ladder with dog do do for lube, you will go inaccurate long before me. Is that RPMs? . Now when it does, you are launching a bad .... bullet .... badly. So the slower you turn it from twist rate, the more accurate it is going to look. But the slower you turn it in the barrel, the less bad the bullet will be too and the less requirements on lube and hardness and rifling height too. Launch better bullets than someone else and you will have a higher RPM and velocity level. But it is still a bad launch that can be made better if you change your choices as Bob says.

That is the RPM syndrome. Don't change anything, and you are screwed as you go up. Happens with cast or jacketed eventually. Each individual makes the call. What people seldom realize is the their low velocity efforts can be improved also if you just understood and knew what to correct. That's what HV teaches is how to alter things for better results no matter what the velocity level. So "the zone" is the "easiest accuracy", not "best accuracy" from our point of view.

RPM syndrome is really an equipment and a reloader failure index. You can be the best reloader in the world with poor equipment and get good results in the zone. You can be a crappy reloader with good equipment and perform well there too. But it takes everything to put it all together as you move up. When you do, you can turn some high numbers. But clearly high velocity with the lowest RPMs has a broader spectrum. That still doesn't make it RPMs. Best accuracy occurs just before leading begins. Problem is the gas check doesn't let you see that point as it takes it out with it to hide the evidence. :grin: So at that point it becomes balance and RPMs. :grin:


A very good write-up John.

Lets see some more groups Ralf.

Larry posted:
Also, some don't consider 2000 fps as "high velocity". Why don't you push your bullets up to 2500 fps and see what happens.

Hmmm... Bass already did this, 2600 fps with 1.5" accuracy. Lets see, your the guy that claims you can't get good accuracy above about 1800 fps, at least from your writing. Several guys have and have posted excellent groups, far better than anything you've shown even within your supposed range at low velocity. So that looks like your theory remains just a theory, to you at least. Maybe Bass and BABore and I are right. You probably need some good boolits to shoot.

[Bass Ackward]

Jeeze Bass, you must love typing. I said the same thing a few hundred posts ago with just four words, "Crap In, Crap Out".



BA,


:bigsmyl2:


Yes. I understand. The conversation is directed to Larry. And I know he can interpret that statement from his experience. But I am writing for the other folks following this that may not be. Or the guys who may revisit this subject next year as bullet costs continue to rise.

A lot of things are posted here and quite honestly are very abrupt in nature if you are trying to put it all together. There is one guy here that just LOVES to make you think. He shall be nameless. :grin: My wife does that to me by asking me if I am hungry. That may be a legitimate question. Or it can have subliminals like she is hungry and wants to eat now. She may want to start dinner. Or she may want to go out. I NEVER guess right there either. :grin: So I don't want anyone else to be subject to that misery too. :grin: If you get tired of reading, quit!!! :grin:

Problem is that I right poorly. And I tend to piss people off. Sorry, I should have paid more attention in school. Woulda coulda. :grin:

I have changed my opinion on this subject somewhat because of this thread. And I believe that it has helped me immensely. I now believe that I have a better understanding of instability. My opinion, at this day and time, is that instability is really the same whether it is high or low RPMs. Instability is instability. I actually see RPMs as my friend. When in doubt, speed up. Just do what it takes to get there without destroying my bullet. :grin:

And really, I was trying to mitigate between Larry and Ralf and get them to unite against me and it just carried on a bit. :grin:

[Larry Gibson]

Bass

We are back to square one.

You and several others have not listened to a single thing I've said. Good day.

Larry Gibson

[Tiger]

Larry

You something else hahahahaha. Yes back at square one because now you don't listen. You do the same thing you tell me. That is you are not reading what my last post say. The first targets with many shots was to show what many different loadings do. I say that and you say mostly what bad group that I should slow velocity down and see what my rifle really does. Next target was the important one. That one WAS to show you high rpm. Yeah one outside shot big deal . I did not weigh each bullet or let us say do all the necessary things one can do to assemble most accurate cartridge. In fact Larry while sizing bullet I dropped container on cement floor. Maybe I damage some hey? Let me just tell you that my rifle will shoot that same small group over and over. Next targets I say to show what brass change done. Maybe you are not getting the picture but I know you have to know this. Many things can change the outcome of your group with cast. Okay then you say my overall all shooting is 2 inches. No not so. I just explain all targets exluding small one. That remind me. The last target with outside shot I mark number 9 was not cause by anything other then myself. I squeezed trigger wrong on that one and I knew it and it showed it. That was not because of any other influence in the assembled load. Back to small group that is my average. So if you except that then your excuse was let us up the velocity. How far I have to go to make you happy Larry? That small group was up in the 180000 rpm range. Now you want me to up velocity to 2500 fps. That put me well in 200000 range. To be correct 225000 rpm. But I know if I do this you still not be satisfied but come up with more excuses. But I tell you what I will try.

I did not mean by saying the problem with you doing the test was that you were shooting them meant you were a bad shooter. I meant that if I did with my rifles if Bass did it with his if Runfiverun did it with his and so on that all groups would be different. Before you say I say for you. You will say we will still see a pattern.

Larry saying that it is easier or you get better accuracy at lower velocity and lower rpm is same as saying one can drive an automobile better at slower speeds.

Ralf

[Larry Gibson]

Ralf

You are da man! You are legend! What a dude man! I bow to your obvious expertise in all matters of cast bullets. That should make you a happy camper.

Larry Gibson

[BABore]

BA,


:bigsmyl2:


Yes. I understand. The conversation is directed to Larry. And I know he can interpret that statement from his experience. Interpret is not a good word here. But I am writing for the other folks following this that may not be. Or the guys who may revisit this subject next year as bullet costs continue to rise.

A lot of things are posted here and quite honestly are very abrupt in nature if you are trying to put it all together. There is one guy here that just LOVES to make you think. He shall be nameless. :grin: Let me guess, he's both older and crankier than me. My wife does that to me by asking me if I am hungry. That may be a legitimate question. Or it can have subliminals like she is hungry and wants to eat now. She may want to start dinner. Or she may want to go out. I NEVER guess right there either. :grin: I do all the cooking, so my answer is always right, "I will be when I get it cooked". So I don't want anyone else to be subject to that misery too. :grin: If you get tired of reading, quit!!! :grin:

Problem is that I right poorly. And I tend to piss people off. Sorry, I should have paid more attention in school. Woulda coulda. :grin:

I have changed my opinion on this subject somewhat because of this thread. And I believe that it has helped me immensely. I now believe that I have a better understanding of instability. My opinion, at this day and time, is that instability is really the same whether it is high or low RPMs. Yep! Pointed this very thing out in a related thread. Mentioned a LV revolver load that went from unstable to stable with a mere 3-4 Bhn softer alloy. The whole point was missed cause I wasn't above some imaginary threshold. Instability is instability. I actually see RPMs as my friend. When in doubt, speed up. Just do what it takes to get there without destroying my bullet. :grin:

And really, I was trying to mitigate between Larry and Ralf and get them to unite against me and it just carried on a bit. :grin:


What would be a textbook thread would be how to take a typical rifle and make it shoot HV cast. Step by step. One variable at a time. In reality all of this information has already been posted and is here for the pickings. New casters should be made aware of the limitations of off-the-shelf boolit designs, techniques, and book information. Sometimes things fit and it may work. If'in it doesn't, you don't have to give up and throw your hands in the air. There are techniques to achieve HV and they don't all swirl around one little thing. Lots of interacting variables that all have to be addressed for sucess. Simply stuffing more powder in a case is jacketed bullet mentality. Does it even work there? Not always. How come? Is it RPM's or velocity? NOT! Not when you can simply switch powders and get even higher velocities before accuracy peters out. The very first thing I realized when I started casting is "Crap" I got a whole new batch of variable to deal with.

[Tiger]

Ralf

You are da man! You are legend! What a dude man! I bow to your obvious expertise in all matters of cast bullets. That should make you a happy camper.

Larry Gibson

Larry

That is elementary psychology. Nice try although it may fool your jurors to look badly at me. Not the smart ones though.

BaBore says it best and I say some of the things he said many times over. Like I say long ago you are wasting your time. I too waste my time on last targets but hey this new rifle and interesting to see what it does with cast although not built for that reason.

Ralf

[Bass Ackward]

Bass

We are back to square one.

You and several others have not listened to a single thing I've said. Good day.

Larry Gibson


Larry,

You said testing was still on going and not to change anything or come to any conclusions until you finished testing and see if that testing indicates a change is warranted.

This is what I have done. The only difference here is that I acknowledged a stability or RPM flaw to my logic that I should have been considering all along. That correction can be, and has been made. And this is my thanks to you for that much so far.

[carpetman]

My wife watches a soap opera and I avoid it as much as possible. After years and years of "As The World Turns" even avoiding it, you hear a little here and there. Some characters die off and amazingly later on come back as someone else. This thread has become such. Long time back we got "The Last Word on the subject" from an individual, but more words keep coming. Heck some people seem to enjoy soaps and obviously are enjoying this one. But could we come up with a snappier title? Maybe "As The Bullet Turns". Perhaps some of the cast could change their name to Victor Newman. Annual award given and the grammy would have to be a cast bullet or maybe in honor of Medic 44 a lead hammer.

[Larry Gibson]

BABore

I am awe struck;

"What would be a textbook thread would be how to take a typical rifle and make it shoot HV cast. Step by step. One variable at a time. In reality all of this information has already been posted and is here for the pickings. New casters should be made aware of the limitations of off-the-shelf boolit designs, techniques, and book information. Sometimes things fit and it may work. If'in it doesn't, you don't have to give up and throw your hands in the air. There are techniques to achieve HV and they don't all swirl around one little thing."

Man oh man what a concept! Run a test with one variable at a time! New casters should be made aware! Off the shelf limitations! There are techniques! Swirl around one little thing! Wow!!!! What a conceptual grasp of the situation you have! What a novel concept!

Ralf move over, you are no longer "da man"!

Must be why BABore is one of the few resident experts around here, eh!

Now why didn't I think of doing a test like that!

Larry Gibson

[Larry Gibson]

Carpetman

Nice to see you watch "soaps".

Larry Gibson

[45 2.1]

Now why didn't I think of doing a test like that!
Larry Gibson

Actually your the one who said it couldn't be done, so that would be a very good reason why you didn't think about it.

[BABore]

BABore

I am awe struck;

"What would be a textbook thread would be how to take a typical rifle and make it shoot HV cast. Step by step. One variable at a time. In reality all of this information has already been posted and is here for the pickings. New casters should be made aware of the limitations of off-the-shelf boolit designs, techniques, and book information. Sometimes things fit and it may work. If'in it doesn't, you don't have to give up and throw your hands in the air. There are techniques to achieve HV and they don't all swirl around one little thing."

Man oh man what a concept! Run a test with one variable at a time! New casters should be made aware! Off the shelf limitations! There are techniques! Swirl around one little thing! Wow!!!! What a conceptual grasp of the situation you have! What a novel concept!

Ralf move over, you are no longer "da man"!

Must be why BABore is one of the few resident experts around here, eh!

Now why didn't I think of doing a test like that!

Larry Gibson


Just thought it would be a novel way to demonstrate how it can and has been done, as opposed to telling everyone how it can't.

As to why you didn't think of doing a test like that is beyond me. A man of your vast experience and all. You made grand claims of how your test was to be carried out and advanced, stating that you were open minded and would withhold any judgement until finished, yet you have already made up your mind and said as much. IMO it was made up before you started.

[Larry Gibson]

Actually your the one who said it couldn't be done, so that would be a very good reason why you didn't think about it.

Quite wrong 45 2.1.

Had you ever bothered to read what I've written yould know that the test I'm conducting is exactly as BABore mentions this test should be done. I also accomplish accurate measurements while conducting the test to further validate the results.

You would also know that I never said it couldn't be done, assuming you mean accuracy with a cast bullet at HV by "it". Again if you read what I've written you would find I intend to determine the effect of RPM. Then I intend to conduct tests to determine what can be done to negate those effects, one thing at a time.

However, since you are also one of the few resident experts on this forum you formed a preconceived notion even before the test was started. Problem is, your notion is wrong.

This test revolves around the often asked question as to why a shooter can't get any accuarcy above 1800-1900 fps with his 10" twist '06 using a cast bullet such as 311291 (you may substitute another bullet if you like but the results are the same). This shooter wants a good practice cast bullet load that shoots 2500+ fps and doesn't understand why he can't get good accuracy at that velocity. He asks what can be done to make his 311291 shoot good at 2500+ fps. This test seeks to show him why he will not get good accuracy out of a 311291 in a 10" twist '06. In plain English, I'm seeking the answer.

This test also will further be conducted to see what things we can do to improve accuracy at 2500+ fps with 311291 and a couple other bullets. This test will also involve shooting regular cast bullets of other calibers at velocity intervals from below on up through the RPM threshold to ascertain it's effect on them.

I really do not hold out much hope that we will ever see good accuracy out of such cast bullets at that velocity and over 180,000 RPM. However perhaps we can get reasonable accuracy, we shall see. This leads me to one other thing; I've asked you this before and you've failed to respond. Have you shot a 311291 (or a similar bullet) with good accuracy at 2500+ fps out of a 10" twist '06? If so could you enlighten us with the facts on how you did it. Your usual response of some of us can and most can't is not really useful information.

But then who am I to say what is useful and what isn't when it is from one of our few resident experts.

I guess I'll just continue with the test I never thought of.

Larry Gibson

[Larry Gibson]

BABore

It still hasn't entered your mind that you described the test I am conducting, has it?

As to; "telling everyone how it can't." Isn't that the same as "New casters should be made aware of the limitations of off-the-shelf boolit designs, techniques, and book information"? Or perhaps you can show us how to get accuracy with a regular cast bullet at 2500+ fps out of a 10" twist '06?

Yes my mind was pretty much made up before I started the test. I have been seeing the effect of the RPM threshold for many, many years. You have too as has everyone else. I am trying to get a real answer instead of some mumbo jumbo about special bullets, get a new barrel with a throat that fits, change lube, change powder, change alloy etc. None of that will make Johnny come lately's 311291 shoot accurately at 2500+ fps and everyone here knows it. So when Johnny come lately asks that question I want to provide facts that he can deal with, not mumbo jumbo that will not help him at all.

Now, the test isn't complete and you and the other resident experts want me to belly up and say it isn't so. The evidence of the first part of the test is quite clear. You, Bass, 45 2.1, Ralf and leftiye can argue tops, trains, planes and auto's all you want but I am sticking with what cast bullets do. The results of the first part of this test shows clearly that RPM above a certain threshold is the cause of the worsening inaccuracy with regular cast bullets.

As I've said the first part of the test does indeed demonstrate it is RPM and it demonstrates the threshold. I have indeed said that over and over again to the beggings of the self appointed resident experts here including you. But more importantly I also said over and over and over to you few resident experts that if the evidence of the test shows I am wrong I will be the first to admit it. All of you self appointed experts seem to conveiniently forget that as you continue this harangue. I wonder why you all just can't be patient and watch me fail? Could it be that if I don't fail and do prove that it is RPM and a RPM threshold does exist that you self appointed resident experts would then be wrong? Could it be you all are afraid that as I go through testing each item with actual measurements to back it up and find some of the many things you recommend don't work that you will be shown wrong? I think Shakespear said something about "me think thou doeth protest too much."

At the end of the test if I am wrong I will admit it. The question is; will the rest of you resident experts admit you're wrong? Don't bother to answer, you all already have.

Larry Gibson

[Tiger]

Larry,

What would make one style bullet different from high rpm effect then another style? Some will say bullet length. So far I am not seeing that. The bullet my friend make the mold for is quite long of 6.5. Larry it is not real easy let me rephrase that it is not as easy as in your country for me to get firearms and reloading materials. I say this because you asked for higher velocity test from me. You are correct that the 8x57 take apart powder is in 4895 range. Maybe I try that and we see.

Re-Loading!
A re-loading permit (also sometimes referred to as a powder license) in Germany can be obtained from the local
weapon’s authorities (city hall or county office). A prerequisite is attending a re-loading class and passing the
exam. Periodic courses are arranged for by various Hunting, Fishing & Sport Shooting Facilities. The course is
generally conducted over 2 days and costs approx. € 150. Such a permit allows purchase and ownership of reloading
equipment, primers, black or nitro cellulose powder for the manufacture of ammunition. During the
course you will also be taught what to observe if you intend to give away or sell self-made ammunition.

In order to legally possess POF in Germany you must obtain a German Weapons Possession Card
(Waffenbesitzkarte/WBK). Such a card is NOT a concealed or a non-concealed weapons permit (meaning it is
not a permit to carry POF around with you while shopping, etc.). A WBK is a permit that allows you to purchase
certain POF, use them on ranges (or in the case of hunters, while hunting), store them at home (in a weapons
safe meeting German security specifications), and transport them from home, in the trunk of your car (POF kept
in a case and separate from ammo) to a range, hunting area, or gun smith. It does not permit you to have with
you or even carry POF inside the vehicle while driving around, going shopping, etc. If you intend to use only
loaner guns from the Hunting, Fishing & Sport Shooting Facilities to shoot at their ranges you do not need a
permit (WBK). If you want to purchase your own POF or bring POF you own from the US into Germany you will
have to be a sport shooter or a hunter and be in possession of a WBK before you take control of the weapon in
Germany. This WBK is only a valid document in Germany.

Ammunition!
As stated above, hunters may purchase any legal long gun ammo (and take it home) – their hunting license
serves as an ammo purchase permit. Any ammo for hand guns may only be in the hands of hunters if a hand
gun has been entered on a WBK and the ammo stamp for that hand gun has been applied to that entry. Sport
shooters may only purchase (and take home) ammo for POF that have been entered in their WBK and that have
the ammo stamp applied to those entries. The only exceptions in cases ammo stamps for a particular caliber
have not been obtained are:
- Ammo purchases at the range for immediate use at the range (you may not take ammo away from the
range).
- Ammo for signal/starter pistols (blanks, tear gas, signal)
- Having obtained a re-loading permit [Sprengstofferwerbschein] (also called “powder license,” see below)
which serves as ammo permit for any legal ammo.
In other words, if you are not at a range you may only have ammo if you have the proper permit (hunting
license for long gun ammo, or ammo stamp for a particular caliber in WBK, or a re-loading permit).

This is just generalization.

Ralf

[Tiger]

Larry

We talked much about rpm and stability. We talked about what bullets defects may do. This all remind me of picture I have you and forgot about.
This is picture of HK 4.6x36mm that I am sure most have not heard about.
It was designed for a precursor of the G 11. After looking at tips of bullet in picture tell me what they were planning.

Ralf

http://i285.photobucket.com/albums/ll42/Ralftiger/46x36.jpg

[Larry Gibson]

Ralf

Thank you for the dissertation on shooting in Germany. However, one question still remains; are you conducting the tests at 100 meters? Use the surplus 8x57 powder to run the test I mentioned to you from 1400 fps up through 2500 fps in 100 fps increments or however high your cartridge will take you with that powder. Graph the groups size vs RPM, then group size vs velocity. Show us the graphs, then we'll talk.

My only guess (that's all it is so please no long discussion please) is that the nose is altered to accentuate tumbling when soft tissue is hit. I had read that this was tried and that was the reason given. My guess is you have a picture of the altered bullets used for that reason. However there are other possibilities to guess at. I'll not guess at this time as I'm busy conducting a more important test.

Larry Gibson

[Tiger]

Larry

Yes shooting done at 100 meters.

I assume bullet tips for tumbling in tissue too. My point is the ammunition must still meet accuracy requires and one is let to believe that tip disfigurement would not help it any.

Late for me more next time.

Ralf

[Larry Gibson]

Ralf

It has been known for some time that while some inaccuracy results from bullet nose deformation it is usually very slight over practical ranges. Given the less than stringent accuracy requirements of military ammunition the afore mentioned ammuntion probably met accuracy standards. It is my understanding that there is some question as to whether this type of ammuntion meets with the provisions of the Hague Accords of which the U.S. is not a signatory but generally abides by. Interesting concept though and perhaps useful and functional given the short range expectancy of the ammunition/gun combination in an urban warfare scenario.

Thank you for the answer to the test range.

Larry Gibson

[45 2.1]

Larry wrote:
Had you ever bothered to read what I've written yould know that the test I'm conducting is exactly as BABore mentions this test should be done. I also accomplish accurate measurements while conducting the test to further validate the results.
I have read what you've written. Exactly when were you going to take accuracy into account? Your statements morph along with the wind and rain without credibility over the course of your story.

The results of the first part of this test shows clearly that RPM above a certain threshold is the cause of the worsening inaccuracy with regular cast bullets.
It shows several things you steadfastly refuse to take into account or don't know about.

so please no long discussion please
Please, take your own advice.

[Bass Ackward]

Ray: The proviso was something "I felt" I could add. Just like a democrat that always changes the rules. :grin: I have changed my outlook.

RPMs is a stability issue.

The enemy of stabilized flight is three forces. We know from centuries of research the effect crowns have on accuracy because of pressure. If pressure alters your bullets launch so that yaw is increased, then pressure is going to be the greater force that kills you. But high pressure loads can be accurate so this isn't everything.

If your load unbalances the bullet or it strips or deforms from the twist rate forces in the bore, then RPMs will become more of a factor to inaccuracy. But since accurate high RPM loads can be produced, it can be overcome too.

A 30 MPH wind at a 90 degree angle moves a 30 caliber bullet 2" at 100 yards. So a 2000 MPH wind at a vector is going to have a course changing effect as well with nose shape and BC being determinants of the over all effect. But poor BC bullets can be shot well too especially at lower velocities.

Which one of those forces has the most effect at any one time changes as the conditions of the load change This is why bore diameter plays a key part to velocity. A higher accurate high velocity level is possible with a 22 caliber and gets increasingly difficult to achieve as bore diameter increases without lowering velocity levels considering all bullets are molded with the same methods and imperfections.

The stability or lack of it has absolutely nothing to do with a zone or a velocity level as stabilized flight can occur at any point. The difference between a 1600 fps load with a 311284 that shoots load " A " into 1 1/2" and a load " B " that clocks 1600 fps that shoots 1" is still a factor or combination of all three forces that can not be separated. Just the shooter decides when his actions produces accuracy that is satisfactory to him.

Can we say that there is an RPM zone? Yes, if you want to. You can make a case for it
Can we say that there is a muzzle pressure zone? Yes, if you want to. You can make a case for this too.
Can we say that higher BC bullets will always be easier to develop accurate loads for at higher velocity levels than blunt bullets? And smaller caliber bullets catch less wind than larger diameters? Yes, if you want to. You can make a case for this as well.

But the problem is that none of those statements would be fact or true in every case. Only generalizations that can all be wrong under the right conditions. When those things occur with other facets of cast shooting, we call them old wives tales.

Which of those forces is the most responsible for inaccuracy? The correct answer is the one that is preventing "the best" accuracy at any velocity level. Failure to properly diagnose and or correct and control any of those forces, lowers your accuracy level and velocity ceiling.

So if all those statements can be wrong to varying degrees, why propagate them in the first place?

How's that Larry?

[Larry Gibson]

45 2.1

"Exactly when were you going to take accuracy into account?"

I've answered this question to you and others numerous times already. Perhaps since you are reading (at least you say you are) what I've written a little comprehension would be in order.

To answer the question again; in the first test accuracy was considered. The tests were conducted from a low velocity RPM range up through a high velocity/RPM range. The accuracy of each group at each velocity/RPM was measured and compared to the accuracy of each group at the other velocity/RPM of that same rifle. The accuracy for the test was to observe the comparative loss of accuracy of each rifle unto itself. The test was not to find the "best accuracy" for each rifle. The accuracy of all the groups of each rifle was then compared to BC, pressure, velocity and RPM. And lastly the comparative accuracy and accuracy loss was then compared between rifles. That you seem to persistantly think, in your expert opinion, the test should have been for "accuracy" is just that, your opinion. The test was not for that and needed not to be. The test results verify that.

Let me say that agian just in case you missed it; the first test was not to determine the best accuracy for each rifle but to determine when accuraccy was lost, how much accuracy was lost with each rifle (comparative to itself) and to isolate RPM to see if it was the cause. Determining the "most accurate load" was not needed to detemine these.

Accuracy was also taken into account in the test Bass requested and stated infatically that test prove whether it was RPM or not that was causing the inaccuracy of cast bullets. Of course when the results proved it was RPM then he reneged. It was a measurement of accuracy loss during that test that was considered. Again, a "best accuracy" load was not necessary.

Now as to "best accuracy"; I have stated in Chapter 1 and Chapter 2 and I don't know how many times during this thread that when the initial testing to determine if the RPM Threshold does exist or not then I will begin accuracy testing. I will test one change at a time (lubes, powders, primers, seating depth, neck tension, alloys, "nodes" and different cases are on the agenda) to determine which of those really makes any improvement in accuracy. That initial testing for "best accuracy" will be with 311291. I will give it my best shot to improve on the accuracy of 311291 at 2400-2500 fps out of the 10" twist rifle but quite frankly I do not hold much hope for much improvement as I've tried this too many times in the past. The difference here will be with the data collected via the M43. When that testing for accuracy with 311291 is complete I will then switch to 311466 and develope the "best accuracy" load for that bullet in all 3 twists.

I also will test numerous cartridges of different calibers (mentioned several times in this thread) with regular cast bullets to determine If and where their accuracy loss begins and if it is within the RPM threshold. This test will give us a good idea if the RPM threshold is "caliber specific".

"It shows several things you steadfastly refuse to take into account or don't know about."

Several things have been discussed that the test shows. When asked about others I have always given an answer. Simply because you do not like the answer does not mean I "steadfastly do not take them into account". You always fail to present any facts as to why they should be taken into account. Just because you think so is not a good reason. Oh but excuse me, you are one of the self annointed resident experts here so perhaps I should take them into account. Ok, let's give it a try. Give me one thing I have not taken into account and back it up with facts (please, facts here...not you own opinion). If your facts refute the results of the test then we'll take another look at it. Ok?

I doubt there are things there I don't know about. That seems to be one of your usual responses to those who disagree. You should try presenting some facts instead of just insinuating the other person is stupid or ignorant and only you and the other resident experts are smart enough or have the ability to shoot anything accurate at HV.

If that is a long dissertation it is so you and others will stop the harangue about my not answering your questions. I really don't care whether you nor the others like the answer as I've never been known for my political correctness (a euphanism for blowing smoke up someone's you know what).

That is the answer to your question.

Larry Gibson

[45 2.1]

Well Larry, you seem to be the most politically correct guy I know. You've spent an enormous amount of band width telling everyone that RPMs are the cause of HV inaccuracy without telling them how to get around it irregardless of your test. You can't seem to shoot HV accurately as you have pointed out by your own definitions, so either find out how to do it or take lessons from someone else. The point you made at one time was that you wanted to be able to tell someone how to get better accuracy when they faced this situation.

[Tiger]

Well Larry, you seem to be the most politically correct guy I know. You've spent an enormous amount of band width telling everyone that RPMs are the cause of HV inaccuracy without telling them how to get around it irregardless of your test. You can't seem to shoot HV accurately as you have pointed out by your own definitions, so either find out how to do it or take lessons from someone else. The point you made at one time was that you wanted to be able to tell someone how to get better accuracy when they faced this situation.


Hallo 45 2.1

Maybe another way to say is Larry was discouraging shooters from high velocity high rpm shooting because he self imposed a rpm threshold limit.

Larry you do know things but you don't know how to intermix them to get high velocity high rpm or even just high rpm without such high velocity. Take alloy for example. You know that you must go harder for the high end. Maybe you will go from wheel weights to say lino type. That is not always correct. You have to learn to blend the alloy. If say a wheel weight alloy not suitable for velocity or rpm you just not go to lino type straight off. Lino type is not a cure all. You must blend till you find it. Now do not take this wrong that I say you said go straight to lino type hey. There are so many things that influence cast accuracy at high velocity and rpm. Your 50/50 alox/beeswax lube has it limit you know what it is Larry? Maybe certain lubes have velocity but also rpm limit hey? Maybe if used one of the hard specialty lubes on your 10 twist test things come out different.

By way I now blend some harder alloy for my higher velocity in 6.5x47. I feel this because the bearing band on bullet I use not enough and I want more strength. I will not go to shorter bullet like many have suggested. I will make this bullet work. I believe if all else right length plays no part.

Ralf

[Larry Gibson]

45 2.1 and Ralf

You two are just cracking me up! First Bass and you 45 2.1 go on and on throughout this thread and others saying I can't shoot accuratly at HV because Bass can get MOA with a custom cast bullet (BTW Ralf, is your bullet cast out of an offr the shelf regular mould or is it a custom made one?) on an 80+ degree day only if shooting a few rounds. Then Bass comes back with 2 moa and that is all of a sudden ok accuracy. Ralf likes his 2-3 moa accuracy and perhaps his 6+ moa 20 shot group. 45. 2.1, when are you going to harangue the two of them about accuracy?

I have stated numerous times that I get reasonable accuracy at HV. How about 2" groups at 2592 fps out of my 10" twist '06? That is consistantly 2 moa regardless of the temperature, which way I'm facing or whether I borrow my wifes rifle (as Bass does). That's 2 moa anytime I go out. That's 186,000+ RPM BTW. Pretty good eh? Yes it is but the point is that rifle with that same bullet shoots 1 moa at 1838 fps which is in the RPM threshold at 132,000 RPM. That's what you self appointed experts have a problem with; you don't see the point. The point being as I've always said; accuracy will be better in or below the RPM threshold. I never did say it would be horrible above the RPM threshold or even unreasonable. You guys can't read and comprehend at the same time.

So Ralf, what is it that I exactly do not know about "how to intermix"? My groups are a consistant 2 moa at a higher velocity than yours, about 600 fps higher. That's pretty much what you mean by "high velocity high rpm or even just high rpm without such high velocity" isn't it? I also get 2 moa quite consistantly with my 6.5 Swede with 7.5" twist at 1900-2000 fps. That is the same as you're doing except mine doesn't shoot 6+ moa groups, it shoots consistant 2 moa groups. So just what is you point and just where do you get off telling me I don't know what I am doing. I've gone from WWs to WWs + tin to #2 alloy to linotype and the results are all pretty much the same. The harder alloy lets you push into the RPM threshold a little farther but RPM still gets you in the end. Best accuracy will still be in or below the RPM threshold as I've said over and over and over again ad nauseum.

I do wish you self appointed experts would get together. Bass and Ralf are happy with less than "best accuracy" and 45 2.1 continues to harangue me about "Exactly when were you going to take accuracy into account". I keep saying that the best accuracy will come in or below the RPM threshold and that reasonable accuracy can be had above it (I have proved that it can). So do you experts want to get together and at least get your harangue straight, eh?

Ralf, I know what the limit is to Javelina lube and 2500 fps is not it. Obviously you don't know that. Note the above regarding the 2 moa consistant groups at 2590 fps...that is with Javelina. I question whether you know anything about lubes simply becase you change lubes 4 times during a 20 shot string and can't track which shot was which. That is a real definitive test. Just shows us a 6+ moa 20 shot group is all. And as you obviousl can't read and comprehend at the same time go back to my last post to 45 2.1; you see that a test of different lubes is on the aganda. Also it is well known in the scientific comunity that for a test to be valid only one thing must be changed. You can't change several things and come up with a valid answer to anything other than you made cahnges. Now if you want to "intermix" things as you did with that 6+ moa group and spout your conclusion as proof of something then be my guest. Problem is that only shows you believe in witchcraft, voodoo or some other mystical way of making assumptions. I'll stick with the scientic method thank you.

Ralf, I'd also suggest you don't waste anymore trying to "make this bullet work". Just ask Bass, he'll tell you your 2-3 moa groups are fine. Ooops, he already has! However if you really want a basis to see what your rifle is capable of then run the test I told you to run. You will then have an accuracy goal to work toward at HV, i.e. a valid comparison to objectively judge the accuracy of you HV loads. Otherwise you are just blowing smoke in a reversable direction into the wind.

Larry Gibson

[45 2.1]

45 2.1 and Ralf

You two are just cracking me up! First Bass and you 45 2.1 go on and on throughout this thread and others saying I can't shoot accuratly at HV because Bass can get MOA with a custom cast bullet (BTW Ralf, is your bullet cast out of an offr the shelf regular mould or is it a custom made one?) on an 80+ degree day only if shooting a few rounds. Then Bass comes back with 2 moa and that is all of a sudden ok accuracy. Ralf likes his 2-3 moa accuracy and perhaps his 6+ moa 20 shot group. 45. 2.1, when are you going to harangue the two of them about accuracy?

I have stated numerous times that I get reasonable accuracy at HV. How about 2" groups at 2592 fps out of my 10" twist '06? That is consistantly 2 moa regardless of the temperature, which way I'm facing or whether I borrow my wifes rifle (as Bass does). That's 2 moa anytime I go out. That's 186,000+ RPM BTW. Pretty good eh? Yes it is but the point is that rifle with that same bullet shoots 1 moa at 1838 fps which is in the RPM threshold at 132,000 RPM. That's what you self appointed experts have a problem with; you don't see the point. The point being as I've always said; accuracy will be better in or below the RPM threshold. I never did say it would be horrible above the RPM threshold or even unreasonable. You guys can't read and comprehend at the same time.

So Ralf, what is it that I exactly do not know about "how to intermix"? My groups are a consistant 2 moa at a higher velocity than yours, about 600 fps higher. That's pretty much what you mean by "high velocity high rpm or even just high rpm without such high velocity" isn't it? I also get 2 moa quite consistantly with my 6.5 Swede with 7.5" twist at 1900-2000 fps. That is the same as you're doing except mine doesn't shoot 6+ moa groups, it shoots consistant 2 moa groups. So just what is you point and just where do you get off tellinng me I don't know what I am doing. I've gone from WWs to WWs + tin to #2 alloy to linotype and the results are all pretty much the same. The harder alloy lets you push into the RPM threshold a little farther but RPM still gets you in the end.

Yes I know what the limit is to Javelina lube and 2500 fps is not it. Note the above regarding the 2 moa consistant groups at 2590 fps...that is with Javelina. I question whether you know anything about lubes simply becase you change lubes 4 times during a 20 shot string and can't track which shot was which. That is a real definitive test. Just shows us a 6+ moa 20 shot group is all. And as you obviousl can't read and comprehend at the same time go back to my last post to 45 2.1; you see that a test of different lubes is on the aganda. Also it is well known in the scientific comunity that for a test to be valid only one thing must be changed. You can't change several things and come up with a valid answer to anything other than you made cahnges. Now if you want to "intermix" things as you did with that 6+ moa group and spout your conclusion as proof of something then be my guest. Problem is that only shows you believe in witchcraft, voodoo or some other mystical way of making assumptions. I'll stick with the scientic method thank you.

I wouldn't waste anymore trying to "make this bullet work". Just ask Bass, he'll tell you your 2-3 moa groups are fine. However if you really want a basis to see what your rifle is capable of then run the test I told you to. You will then have an accuracy goal to work toward at HV, i.e. a valid comparison to objectively judge the accuracy of you HV loads. Other wise you are just blowing smoke in a reversable direction into the wind.

Larry Gibson

If 2 MOA is what your crowing about, you have a lot to learn.

[Larry Gibson]

45 2.1

"You've spent an enormous amount of band width telling everyone that RPMs are the cause of HV inaccuracy without telling them how to get around it irregardless of your test."

Just can't wait for the test to get done can you.......

"The point you made at one time was that you wanted to be able to tell someone how to get better accuracy when they faced this situation."

You are apparently comprehend challenged again. I have stated that I want to tell johnny come lately that he won't get the same accuracy with 311291 (or other regular cast bullet) at 2500 fps that he gets at 1800 fps out of his 10" twist barrel '06. I want to tell him why he won't because that's all he wants to know is why he can't with his rifle and that bullet. I don't want to blow smoke up his you know what like you self appointed resident experts do about getting a new rifle, using harder alloy, changing lubes, buying a custom mould, adjusting nodes or any of the other things you experts mention. I will tell him why he won't get the same accuracy with 311291 at 2500 fps that he gets at 1800 fps. Then I will discuss what he might do to achieve a little better accuracy at a somewhat lessor velocity with that bullet in his rifle. That will answer his question. I will back up what I tell him with facts, not opinion, conjecture, old wives tales or witchcraft.

BTW; you haven't shown us how you shoot a 311291 (or other regular cast bullet) accurately at 2500+ fps out of a 10" twist '06 have you.........all you shown us is more harangue.

Larry Gibson

[45 2.1]

BTW; you haven't shown us how you shoot a 311291 (or other regular cast bullet) accurately at 2500+ fps out of a 10" twist '06 have you.........all you shown us is more harangue.

Actually, I have been telling everyone how to do it for over four years. I've had three takers so far. Not to good of odds when other people are running tests and crowing about 2 MOA groups, is it.
And no, I don't care if you finish your test or not, that is something I did long ago and already know where it leads.
If you want to test your so called "regular cast bullet" as you call it, feel free, knock yourself out as its your time. I on the other hand will use my methods and enjoy the fruits of what i've found out. Keep your 2 MOA loads and enjoy yourself also, while you can.......................................

[Larry Gibson]

I had responded to 45 2.1's last message but on further thought deleted that message. It's not worth the time nor the effort to respond to him any further.

Larry Gibson

[runfiverun]

okay 2" flippin groups at H.V.
i was gettin those at 2300 fps without cleaning or leading. [but my little 6# 308 was beating mr to death]
what am i going to do with that???
i can't use the boolit to hunt with it is too brittle, maybe an occasional rock-chuck.
it don't impreass any body. [ maybe the recoil does ]
and it sure wont get me a trophy , unless a pat on the back is a trophy.:[
i can knock down the rams with a 158+gr boolit at 1900....

so iguess what's left is just to say i can do it....

[Tiger]

Larry

I knew you would not understand and that you would interpret my targets wrong. So instead of calling you thick headed or something else let try again.

First that rifle will shoot 5/8 inch groups consistently. How many targets shall I post of that big man? Tell me, how many before you stay quiet with your Ralf shoots 2 inch groups. Come Larry tell me. Then when I post bunch you apologize and say Ralf you can shoot consistent 5/8 groups. Who know Larry maybe smaller. We see with alloy change. Larry by way I want to see those Swede 2 inch group at 2000 fps.

Okay my thick skull American friend until next time. :mrgreen:

Ralf

[Tiger]

okay 2" flippin groups at H.V.
i was gettin those at 2300 fps without cleaning or leading. [but my little 6# 308 was beating mr to death]
what am i going to do with that???
i can't use the boolit to hunt with it is too brittle, maybe an occasional rock-chuck.
it don't impreass any body. [ maybe the recoil does ]
and it sure wont get me a trophy , unless a pat on the back is a trophy.:[
i can knock down the rams with a 158+gr boolit at 1900....

so iguess what's left is just to say i can do it....


Runfiverun

Sorry burst your bubble but Larry reads wrong too. Give me proper made choke on shotgun I get two inch groups with that too. No no my friend. We are talking much smaller groups sorry. Soon as Larry give me number of 5/8 group targets to post and I finish them I will show you.

Ralf

[runfiverun]

tiger
i am not making fun of you at all
i think a 1" group at 100 is pretty good shooting not 3 shots but 5-10
shots.
and i don't care what you do it with. unless we are talking a bench-gun.
i generally use [ since that is all i own ] off the shelf hunting rifles no modifications.
no scopes over 9 power, and they get banged around rained on left behind the seat
of the truck for a month, cleaned and used some more.

just so you know where the 1" came from, i have a couple of old guns that 3" are all
they are capable of jacketed or cast.

so when we talk about accuracy we should, maybe,qualify where the accuracy is coming
from......

[Larry Gibson]

Ralf

Take a hard look at the groups you posted. You discount the flyer as maybe because you dropped the bullets or something. I do not discount flyers unless I call them and then I also factor them in (read the past posts about the flyers I called). You should not discount them either. They tell you something. You did not post any group that was less than 3 moa with the flyers. The first was 6+ moa with 4 cahnges to the load and you can not define what groups belong to what changes. What is wrong to interpret with that? You want to show us the consitancy of your groups? Then post one target with 5 consecutive different groups of the same load. If they are all at 5/8" then maybe you've got something and should shoot international competition. Maybe you and 45 2.1 should shoot as a team and clean every one else's clock, eh? One group at 5/8" inch (and we haven't seen that yet...notice that flyer out there?) is synonomiss with randon luck. Show us consistancy and you will move back into 1st place as "da man".

Run the test I told you to do and then we'll talk. Until then you are just blowing more smoke as you have no basis for accuracy comparison with our rifle in relationship to the RPM threshold question.

Larry Gibson

[Larry Gibson]

Runfiverun

Don't be discouraged as it is obvious the self appointed resident experts will jump on anyone who dares disagree with them. Unfortuneately the majority out there chooses to remain silent as usual. That's ok as we'll keep up the correct type of testing as that is real proof. Seems as if Ralf is confused, he is the one that claims 5/8" groups even though the flyer makes it closer to 3". I only claim 2 moa which on one hand is fine with Bass as long as someone other than me does it. Seems I'm held to a closer standard here. Oh well, like I really care. We shall perceiver to endeavor...or is that endeavor to perceiver?

Larry Gibson

[Tiger]

Larry

Good morning from Germany. Again I have the forum for my breakfast. My wife wonder I have a girl friend. I say yes Larry. hahahahaha

Okay Larry let's take a look at the supposed 5/8 inch target you say is closer to 3 inches before I make you look foolish.

http://i285.photobucket.com/albums/ll42/Ralftiger/65Germany.jpg

That larger circle is 2 and 1/8 inches. To save you measuring picture on your monitor the outside shot make group 1 and 3/8 inch group. How is that closer to 3 inches?

You twist every thing Larry that is how you impress forum members. I bet you I say my targets are black and white you would make a post degrading me and saying my targets are red and yellow. You fool me, you not in the military you in politics.

You see Runfiverun how Larry twist truth. You can determine for your self that group is not closer to 3 inches. Don't let Larry think for you.

I leave you with this Albert Einstein quote Larry

“Whoever undertakes to set himself up as a judge of Truth and Knowledge is shipwrecked by the laughter of the gods.”

Off to work

Ralf

[carpetman]

Tiger----Obviously you are not listening to Larry. You spell consistent correctly.

[runfiverun]

you mean it dunt have an a?

[runfiverun]

tiger
i have some of those targets, sept mine are in english.
it looks like you do stuff like me.
all the wrong ways but still get good results.
i use the wrong lubes, cast wrong , don't have one mold that is a custom one:[
use the wrong powder and the wrong lead mixes.
but somehow manage to get my boolits all the way to the target and they somehow
seem to be near each other.

[Larry Gibson]

Ralf

Well golly gee whiz...I guess you got me! I thought I was referring to the target you posted with the flyer marked as "9" seeing as I was talking about you discounting the flyers and all. Sure did put egg on my face. Can you go home and let me get on with my test without the personal degradations. Nice to know Einstien was thinking about some here. Perhaps the self appointed experts will hear the laughter of the gods (before someone gets on me for being blasphemous, as they have in the past, I'm only repeating Ralf and Einstien and not putting any god before the only God). The facts will speak for themselves, I need not judge them as the experts here have.

BTW; if that was a proposal, I'm already married and so are you (so you say);-)

Larry Gibson

[Tiger]

Runfiverun

Don't be discouraged as it is obvious the self appointed resident experts will jump on anyone who dares disagree with them. Unfortuneately the majority out there chooses to remain silent as usual. That's ok as we'll keep up the correct type of testing as that is real proof. Seems as if Ralf is confused, he is the one that claims 5/8" groups even though the flyer makes it closer to 3". I only claim 2 moa which on one hand is fine with Bass as long as someone other than me does it. Seems I'm held to a closer standard here. Oh well, like I really care. We shall perceiver to endeavor...or is that endeavor to perceiver?

Larry Gibson

Larry

Hahahahahahaha too much. Read what you say. You say Seems as if Ralf is confused, he is the one that claims 5/8" groups even though the flyer makes it closer to 3". Then you go on to say Well golly gee whiz...I guess you got me! I thought I was referring to the target you posted with the flyer marked as "9" seeing as I was talking about you discounting the flyers and all. Sure did put egg on my face. Goodness my American friend which target is it now? [smilie=1:

Runfiverun

Yes I get my targets off of German website like most everyone else. They sell many American products.

Larry yes I am married with one beautiful daughter. In case you wonder my name it chosen after famous German tank in world war two. My Father served as tank mechanic then.

Ralf

[Tiger]

Runfiverun

Here is website I get my targets from.

http://www.oberlandarms.com/index.php

Ralf

[Larry Gibson]

Ralf

Like I said; you got me there. I read what I said and I was thinking of the last target you posted when I typed that just as I said. So you got me. Shall we go back through your posts and see if you've not made a mistake? Perhaps you should take heed of that Einstien quote before you are so gleeful to throw rocks over such simple and meaningless things.

But let's get back to your chosen subject here; your 4 posted targets. Let's see now, we have a 20 shot target that is 6+ moa, a 10 shot target that is 5+ moa, another 10 shot target that is 3 moa and then a 5 shot target that is 1 3/8". Yup Ralf, that sure is proof positive of "that rifle will shoot 5/8 inch groups consistently". So I guess you can go through those targets and pick out any 4 shot group (there's only 4 shots in your 5/8" group) of bullet holes that are 5/8" together and call that "consistently accurate"?

How about showing us five 5 shot 5/8” groups that are shot consecutively? That could be considered consistent. How about two or three 10 shot 5/8” groups? That could be considered consistent. Or how about one 20 shot 5/8” group? That could be considered consistent. No Ralf, I do not say you are confused (that apparently is your own assumption) I say you are claiming BS. Show us real groups that are a “consistent” 5/8” out of that rifle with that bullet at 2000 fps at 100 meters. Doing that will show us something. Claiming “consistent” 5/8” accuracy out of a 4 shot cluster from those 4 targets is BS. Had you fired another 5 shots more than likely that group would have been "consistent" with the others.

Hope you enjoyed your breakfast and the day. I respect your father’s service to his country. I won’t go any farther here as some will get very upset given the side he was on.

Larry Gibson

[Tiger]

Larry

Yes I got you. Okay I have to make up some more bullets then I shoot you more groups.

About the war do you not have the same problem with your country civil war where many from opposing sides are still bitter?

Going through much rain lately so when nice day come and I get loaded up I will shoot more targets.

Ralf

[felix]

I think, and hate to say, that the civil war now-a-days coming on strong is, not about the several southern states doing a succession stunt because of "acquired" aliens, but leaning more towards accepting "illegal" aliens. ... felix

[runfiverun]

Ralf
yes consistent targets are the way to go not one braggin group.

thanks for the link but i don't have a printer, i barely have a computer that works.
the one i use is built out of a bunch of old parts doesn't have sound and basically sucks.

most of the people out west never give the civil war much thought except as part of american history. [ even though my ancestor won a medal of honor in it]

now cowboy and indian stories are a different matter alltogether.

[Larry Gibson]

Ralf

Yes the "war of northern aggression" is still a hot topic for some. Coming from a western state (Oregon) even though it was a Yankee state I was referred to as a "foreigner". As runfiverun mentions most out here don't much think about it. Too bad as the Civil War is waht defined us as a country. Before the Civil war people would say the Unites States are...., after the Civil War everyone said; the United States is......quite a difference that one word makes in that context.

Runfiverun; speaking of cowboys and indians, let us remember it was the M1873 Springfield that made the West safe for the Winchester!

Thing to remember is that all who fought our CiviL War are dead as are mamost all of their direct decendants. Many of those here who fought the German Army in WWII are not dead. Also many here have vivid memories of the war years and the post war "discoveries" of what went on during the war. I recall sometime in the late '80s there was a reunion in Florida of the Marine Division that landed and took Tarawa from the Japanese. Someone saw fit to invite the surviving Japenese officer who was captured to be a speaker. When he got on stage he was soundly booed off the stage. Some memories don't fade and are not forgotten. I've a friend who had two uncles in WWII who both fought in the European Theater, one in the US Army and one in the German Army. He says the families of each are just starting to talk to each other after all these years.

I suppose that's why I won't return to Viet Nam...some memories don't fade and are not forgotten. Many of us could care less about "closure", "healing" and all that touchy feely stuff. May work for some but many of us don't want to kiss and make up.

Kind of off topic but that's ok, sometimes it's just nice to discuss other things. Shows we can be friends, eh?

Larry Gibson

[runfiverun]

i actually find it easier to disagree with some one that i like.
simply because it is easier to teach or learn from someone you can communicate with.
on an even level.

[Tiger]

Larry

I can understand the differences and feeling between the people divided by your civil war. Let me tell you of something most Americans don't have knowledge of. Remember the Wall divided Germany. Then finally the Wall come down. Because of this long separation there had become differences between the west and east Germans. There is now a dislike between them. The Russians took as much they could from East Germany and the people thus their economy is terrible. The West Germans resent having to take care of them. How long with this last who knows.

Do not forget there were and are many Germans that did not want that terrible war. They will often remind you that it was brought on from a crazy mad man from Austria. Remember too that there much difference between common soldier who served in normal service and those that were true Nazis and SS. Said more simple it was upper management that was bad. Nazis are very looked down on by Germany today. We feel a guilt of what the Nazi did and today the good Germans still have this guilt they much carry because of them.

So we put this behind us now and hope never happen again. If you take all empires and wars that have come and gone in the world and grudges are still held then no body like any one. Atrocities are made by all waring countries through out all of history.

Enough let us talk cast shooting.

Ralf

[Larry Gibson]

Ralf

I agree with everything you said.

Larry Gibson

[BOOM BOOM]

HI ALL,

Let me first say that I have not yet had a chance to read all of this! I started out on R5Rs velocity thread, then decided to try and find the original thread and read it.

First I want to say that this is a good experiment that should not be abandoned. But here are a few observations:
Firstly, The scientific method controls variables. It cannot fail to deal with them and still work. You must design the experiment to eliminate as many variables as possible or neutralize them by keeping them constant.
Larry, do not give up this research. This is valuable stuff. But I think we may have some uncontrolled variables which will take a lot of thought to figure out how to control or eliminate.

My second observation is that in order to be fair, one must admit when they haven't considered a variable that could be a causative factor affecting their results.
Let me cite my own experiment on case length shortening. This is regardless of pressure with lead boolits. I had a sample size of about a thousand rounds and got overall case stretching with 90% of the cases. I thought I had a definitive test design, but did not. As pointed out by other board members, I did not measure from the datum line on my 7mm-06 cases. This put my results into question because I was not able to measure this dimension.

I think that other board members here have raised legitimate questions concerning uncontrolled variables that might be alternative causes of the results that you are getting. Unfornutately, I can't offer any quick fixes for this problem without a lot more thought.

Don't give up! This is how the boundaries of human knowledge expand.

[runfiverun]

boom boom there is more see the thread i started called two twists. it intertwines with this one.
then there is the 6.5/w 9" twist thread.

[Larry Gibson]

Boom Boom

I am isolating and testing the variables. I am taking accurate measurements of any effects those variable have on accuracy at high velocity/RPM. That is how a scientific test is conducted. Before making judgement or forming an opinion, just exactly what are the "uncontrolled variables" are you talking about? Where did I say I never "considered a variable"?

In a test there are variables. Some of those variables we can't do much about such as the difference in rifling mentioned. However if that variable remains a constant throughout the test then it is factored in when, as in this instance, we compare the accuracy changes of each twist (type of rfling) on a proportional basis instead of direct comparison. That is controlling the variables we can not isolate and change. That is the scientific accepted method of dealing with those variables we can not isolate and change. I am dealing with scientific methods not witchcraft, voodoo and old wives tales as others are. That is what I've been doing with those variables I can not change. I am isolating those variables we have contol over and testing each one independantly of the others. That is how meaningfull tests are conducted. That is what the 4 antagonists here do not understand, leftiye in particular.

I appreciate your support for this test. However, don't let yourself get sucked into essoteric meaningless variables such as leftiye's .001" (or whatever it was) extra travel at 100 yards if a bullet hit 3" from the center of the group and how since I couldn't measure that then the test results were meaningless. I believe my responses showed how rediculous that was but the point here is we have to remember what we are testing for. Several are confused not understanding what a proportional comparison is (even after explaining it to them) and keep wanting to fall back to a "develope a most accurate load" syndrome.

We are talking 4-5 moa goups here (the 311291 at 2400+ fps out of the 10" twist) so if we test a vaiable and it shows a .2" smaller 10 shot group than with the base line load is that a signicant improvement? Given that if we shoot three 10 shot groups we may get a ES of a 1.5" difference between group size that .2" based on one group is not a significant increase in accuracy. If we were shooting .5" geoups consistantly then that .2" would be significant. In the case at hand it is not. Thus what we are looking for when isolating the variables is to see a significant increase in accuracy that is below the average group size of the base load. That is exactly what we see when we shoot the same 4-5 moa load out of a 14" twist and it produces sub moa to 1.5 moa accuracy. The only variable changed was the twist which controlled the RPM. There was a very significant improvement in accuracy. That improvement based on the isolation of RPM demonstrates that RPM is a very significant factor. If the other factors isolated and tested show no improvement in accuracy then the conclusion is that RPM is causing the inaccuracy. That is how we conduct a test, isolate variables, test those variables and draw the correct conclusion from the test. It is quite easy to isolate the variables we can control and test them. That is precisely what I am doing. I'll ask you to just pay atttention to the facts not essoteric concepts. During this test two of the long held concepts I've had have already been proven not correct.

Larry Gibson

[leftiye]

I am isolating and testing the variables. I am taking accurate measurements of any effects those variable have on accuracy at high velocity/RPM. That is how a scientific test is conducted. Before making judgement or forming an opinion, just exactly what are the "uncontrolled variables" are you talking about? Where did I say I never "considered a variable"? L.G.

Right. I've outlined all kinds of places where your test even hides variables instead of testing them. All of the factors that have always been known to cause inaccuracy, your test ignores. You may be researching the effects of rpm, but these factors that you refuse to consider should be considered in the sense that they still pollute your test. They didn't just take a vacation because you didn't consider them. That is what is meant by controlling variables. They must be neutralized so that they can't interfere, not just ruled out!

[leftiye]

However if that variable remains a constant throughout the test then it is factored in when, as in this instance, we compare the accuracy changes of each twist (type of rfling) on a proportional basis instead of direct comparison. That is controlling the variables we can not isolate and change. That is the scientific accepted method of dealing with those variables we can not isolate and change. I am dealing with scientific methods not witchcraft, voodoo and old wives tales as others are. That is what I've been doing with those variables I can not change. I am isolating those variables we have contol over and testing each one independantly of the others. That is how meaningfull tests are conducted. That is what the 4 antagonists here do not understand, leftiye in particular". L.G.

This would be fine - IF THOSE OTHER VARIABLES REMAINED UNCHANGING throughout your test. You have made no provisions for keeping them constant, nor have you any way of monitoring them to see if they have changed

Speaking of witchcraft, majic and voodoo; have you yet figured out how centrifugal force ALONE causes inaccuracy without causing instability? Remember, you say that ballistic coefficient monitoring controls for any differences in boolit stability. Now do you know what the .001" was about yet? Prunes anybody?

[Larry Gibson]

"You have made no provisions for keeping them constant, nor have you any way of monitoring them to see if they have changed"

I'm sure it's obvious to everyone that Leftiye has no idea what I do, what I've been doing, how I do it and how I reload or really much of anything. He has no concept of whether I control the variables or not. He is just making his own assumption based on his own opinions. If he would bother to read what I've written he would see how I do control the variables. He is still confused. Too bad, I've wasted enough time on him.

Leftiye

I have answered that question numerous times and you can't understand. Try the section in a Hornady manual. It has pictures, perhaps you can understand the pictures. Yes, prunes. They would relieve you of your problem.

Larry Gibson

[joeb33050]

Larry;
I can't follow this any more. How about sending or posting the numbers. Let the interpretation come later. I need the numbers to understand what you've done.
Thanks;
joe b.

[leftiye]

Duh, Larry, So if I'm mistaken then please tell me how you control for all of the factors that aren't being studied in your experiment which still pollute your results. Joe, nobody can follow it because it is two parallel lines , one asking questions challenging larry's test's validity, and the other larry feeding us more oatmeal that doesn't answer the issues and isn't even on subject as to what needed answering.

As 45 2.1 said, (to paraphrase) "The fact that you respond doesn't necessarily qualify what you respond with as an answer." This is 90% of the "answers" that you provide, Larry

[Larry Gibson]

Joe

I will get them mailed off. Sorry for the delay.

leftiye/45 2.1

Whatever you say.......

Larry Gibson

[kens]

Larry,
"RPM Test; a tale with three twists

Chapter 2; Test 1 [311291 of 2/1 alloy]"

What alloy is that, please?
2/1 of what ingredients?
Thanks,

[44man]

Nothing will come of all the tests. Variables will not go away.

[Larry Gibson]

Larry,
"RPM Test; atale with three twists

Chapter 2; Test1 [311291 of 2/1 alloy]"

What alloy is that, please?
2/1 of what ingredients?
Thanks,

If you go back and read my post #1 you will find; The first test was with the 311291 cast of 2 parts WW to 1 partlinotype.

You might also refer to the"sticky"; http://castboolits.gunloads.com/showthread.php?245302-RPM-Threshold-A-Tale-of-Three-Twists-Chapter-II

That is the same basic thread restarted (onrequest) w/o all the extraneous comments that add nothing to the discussion.

Larry Gibson

[Larry Gibson]

Nothing will come of all the tests. Variables will not go away.

But they have come of something. Care to add something pertinent and of value to the discussion such as test results/data of naked cast bullets of ternary alloy at HV with RPMs above 120 - 140,000 that you have conducted?

Larry Gibson