Ideal twist rates for cast boolits vs. jacketed. Different? Why?

[MBTcustom]

This is a pretty deep question that involves so many variables its almost impossibe to answer, but im going to ask it anyway because im trying to get my head around it.
I’m not trying to start a firestorm here, but I would like to get a better handle on rifling twist rates as they pertain to cast lead boolits.
There doesn’t seem to be any tried and true measure of bullet performance vs. twist rate except the Greenhill formula, which seems to be little more than a ballpark guesstimate.

I have called Kreiger and asked where to go to find good information on this subject, and I was told that each projectile is a law unto itself and when ordering a barrel, to call the bullet manufacturer and describe the length and contour of the barrel, and speed of the shot and follow their recommendations for twist rate. But he also said that those numbers can be fudged one way or the other by powder selection etc etc etc. (surprise surprise)

The water gets even muddier when you bring cast boolits into the mix. Each individual caster is the manufacturer in this case, and it seems that the sweet spot of the boolits is dependant on each caster’s alloy, quality and boolit design, which could dramatically affect the ideal rate of twist.

I know that this could be a question that has no answer, but it would be very good if we could hammer out a few basic rules of thumb, that could be used to help make the jump from A to C.

Just in 30 caliber, I have personally witnessed excellent groups being shot at 100 yards (excellent being under 1.5”) with barrels twisted from 8 to 14 (albeit at many different speeds and bullet styles/designs)

The basic rule of thumb that I generally accept as being true are is that if you have a longer projectile/diameter ratio, you need a faster twist.

This rule works for boolits and jacketed, but each style projectile functions in its own window of effectiveness, and when you make the change from jacketed to cast, you have to rewrite the book.
Or perhaps there are problems with the cast lead boolit that mask the issue and make it seem like you have to rewrite the book when in fact the projectiles are following the same patterns regardless of their hardness.

For instance, say we have a 30-06 with a 12 twist barrel, and we know that it likes 175 Sierra Match Kings driven to 2750 FPS. That’s where the groups go to sleep and start bugholing with that particular load. Groups measure .479 MOA.
So then we decide to go to a 220 grain cast lead boolit of similar shape, and find that it works best at about 2000fps, and gives us a group of about 1.5
Now, say we take a 220 grain jacketed bullet and run it right at 2000 FPS. Will we find that it has trouble stabilizing? Will it only give groups of about 1.5” (kinda like the cast lead boolit?) till we start ramping up the speed a little bit?
Furthermore, was the cast lead really working all that well at 2000, or was that just the fastest we could push that particular boolit, cast by that particular booliteer, with that particular alloy before accuracy fell apart due to inconsistencies?

Now, before anybody jumps all over me about the inaccuracy of the above example, please understand that it’s not real, and I dreamed up the whole scenario to try to get the point across and describe something that is very hard to put into words.

I guess what I’m asking is if we are being biased towards cast lead because it has trouble at high RPM? Or do the rules change dramatically when we make the switch? If so, Why?
Are there “RPM nodes” that a certain projectile will settle into, or does rate of twist really have much less to do with the stability of the projectile than barrel harmonics do?

I don’t have the answers, and it’s such a complex issue, it’s hard to even put it all into words.
I would appreciate a civil discussion about this. Feel free to put your two cents in, but please resist the urge to make someone else see things from your point of view.
There is no hard science on this subject, especially for cast lead, so I’m interested in any point of view on the subject.
What am I not considering (take your pick from the 55 gallon drum of variables)?
What’s your opinion? Why do you see it that way?
Thanks!

[geargnasher]

I read that twice and still haven't a clue what you're talking about. There are quite a few good books dedicated to the subject of exterior ballistics, if that's what you're asking.

Gear

[MBTcustom]

There's people getting good results with cast lead at half the velocity of jacketed. WHY?
If I get off on the twist rate just a little with jacketed, it can take a bughole to a 1" group instantly, but not a lead boolit. WHY?

Cast lead seems much more tolerant to twist than jacketed is. Is that the truth, or do we hold cast to a looser standard? Is it just perception?

Oh and I'm thinking more along the lines of interior ballistics I think. Actually, it's kind of the whole enchilada, Exterior and interior and why they work the way they do.

Some say that cast is a whole new ballgame. Some say there is no difference, except that the rules change for slower projectiles no matter what they are made of.
In other words, some people say that a 30-06 in 10 twist will shoot jacketed or cast equally well if you know what you are doing, but very few can get a cast lead boolit to go faster than 2000fps with that twist.
It seems that the ideal projectile/speed changes dramatically when we go to cast.....or does it?

Just thinking out loud.

Of course, if you would rather tell me how to get the wrinkles out of my boolits or why my barrel is leaded, we could talk about that instead?
:kidding:

[243winxb]

High RPM's with cast = Skidding in fast twist barrels made for Jacketed bullets. Easy to see if using this calculator?? http://www.bergerbullets.com/litz/TwistRuleAltWP.php A Lyman 308 dia. 171.5 gr gas checked bullet at 1502 fps to 2000 fps will work ok with a 17 twist barrel. Bullet length of .968" A Hornady jacketed RN 150 gr with a 18 twist is OK from 1960 fps to 2700 fps. Bullet Length of .909" The Sierra jacketed 150 gr Spitzer at 1960 fps needs a 14 twist. At 2700 fps also needs a 14 twist. Bullet length is 1.068" It would be nice if it was this simple. But its not. In the real world, without calculators, testing is the only way to know. Interesting post. Cant wait to see how wrong the above info is. :-)

[MBTcustom]

High RPM's with cast = Skidding in fast twist barrels made for Jacketed bullets. Easy to see if using this calculator?? http://www.bergerbullets.com/litz/TwistRuleAltWP.php A Lyman 308 dia. 171.5 gr gas checked bullet at 1502 fps to 2000 fps will work ok with a 17 twist barrel. Bullet length of .968" A Hornady jacketed RN 150 gr with a 18 twist is OK from 1960 fps to 2700 fps. Bullet Length of .909" The Sierra jacketed 150 gr Spitzer at 1960 fps needs a 8 twist. At 2700 fps a 9 or 8 twist. Bullet length is 1.606" It would be nice if it was this simple. But its not. In the real world, without calculators, testing is the only way to know. Interesting post. Cant wait to see how wrong the above info is. :-)
This is exactly what I mean. Go to jacketed, and suddenly your stabilizing SHORTER projectiles at higher speeds.

[MBTcustom]

OK, so if you take a 175 SMK going 2800fps, according to the calculator, a twist rate of 15.6 will barely stabilize that bullet with a SG value of 1.01
Lets just call it a 16 twist.
Now, drop that back to cast boolit speeds and see what happens.
2400 FPS gives a SG value of .96 which they are calling horribly unstable. Yet some booliteers claim that's exactly where they want to run their cast lead boolits.

So now, punch it in at a standard twist of 10 and bump the fps back up to 2800. You get a SG value of 2.45 which is exceedingly stable. Like heck and gone stable already!
But a cast lead boolit won't run there for whatever reason. We bump the FPS back to the standard > 2000 FPS which gives us a SG of 2.19 which is still hanging right in there in the (comfortable stability) area.

It seems that we would want the fastest twist that we could possibly get away with. Even with cast lead.

What started all this was a conversation that I had with Bjornb about barrel twist. He mentioned that he was looking at getting a 16 twist in a 30 XCB and I was of the opinion that I wouldn't go any slower than 14. The only thing we are fighting is boolit damage at engraving, other than that, I would think that more stability is better.
It's a trade off between external ballistics and internal ballistics. External ballistics wants MORE MORE MORE!!! While internal ballistics wants LESS LESS LESS!!!!

Is there anything else at play here?
Seems the real trick is to get that boolit engraved without damage (or whatever happens in there) and if you can do that, then the faster you can spin the better. More is always better when stabilizing a boolit in flight.
Or is it?
Is there some other factor that is attached to soft lead boolits that jacketed does not have to contend with?
Look at your calculators. They all say the same thing.

[243winxb]

Jacketed bullets go to sleep or stabilize at some point in there flight. Before they stabilize, the nose is running high & left from a right hand twist barrel. The bullet is pushed off course more if the wind hits it before stabilization. Excess RPM's are not your friend. Plus the torque to the whole rifle is more with a faster twist.

[Fluxed]

snipped a whole bunch....
Cant wait to see how wrong the above info is. :-)

I'm generally agreeing with what you wrote but this part must be a typo:
"The Sierra jacketed 150 gr Spitzer at 1960 fps needs a 8 twist. At 2700 fps a 9 or 8 twist. "

[MBTcustom]

Jacketed bullets go to sleep or stabilize at some point in there flight. Before they stabilize, the nose is running high & left from a right hand twist barrel. The bullet is pushed off course more if the wind hits it before stabilization. Excess RPM's are not your friend. Plus the torque to the whole rifle is more with a faster twist.

I'm willing, but why is there no red line for RPM's in the calculator? How blazin fast do you have to be turning in order to have "excess RPM's"? Why does a cast boolit need less RPM's than a jacketed bullet (assuming you get it out of the barrel undamaged)?
I built a rifle for Love life that was a 243MG with a 7.5 twist barrel. The bullet literally made three complete revolutions before it exited the barrel. The bullet was spinning right around 300,000RPM, and it was almost 1/2MOA out to 1000 yards. If ever a bullet was over stabilized, that would be the one eh?
Also, I was under the impression that a bullet would "go to sleep" very soon after exiting the barrel (like this side of 50 yards).

I think that twist can be overdone or underdone, but for a 30 caliber, I wonder if the 10 twist isn't just altogether unnecessarily fast for both cast and jacketed. either that, or it's just about right for jacketed and cast, but we've got to figure out how to get the boolit out of the barrel undamaged in order to realize the "catch all" benefits of the faster twist.

[str8shot426]

I'm willing, but why is there no red line for RPM's in the calculator? How blazin fast do you have to be turning in order to have "excess RPM's"? Why does a cast boolit need less RPM's than a jacketed bullet (assuming you get it out of the barrel undamaged)?
I built a rifle for Love life that was a 243MG with a 7.5 twist barrel. The bullet literally made three complete revolutions before it exited the barrel. The bullet was spinning right around 300,000RPM, and it was almost 1/2MOA out to 1000 yards. If ever a bullet was over stabilized, that would be the one eh?
Also, I was under the impression that a bullet would "go to sleep" very soon after exiting the barrel (like this side of 50 yards).

I think that twist can be overdone or underdone, but for a 30 caliber, I wonder if the 10 twist isn't just altogether unnecessarily fast for both cast and jacketed. either that, or it's just about right for jacketed and cast, but we've got to figure out how to get the boolit out of the barrel undamaged in order to realize the "catch all" benefits of the faster twist.

Twist can be underdone and overdone. Overdone meaning, more than needed to stabilize the projectile. But I do not believe a projectile can be over stabilized.

[243winxb]

Good catch. Bullet length entered was wrong. Its 1.068" I though that didnt look right. A 14 twist for both velocities
I'm generally agreeing with what you wrote but this part must be a typo:
"The Sierra jacketed 150 gr Spitzer at 1960 fps needs a 8 twist. At 2700 fps a 9 or 8 twist. "

[RPRNY]

I want to be respectful but you're sending out those vibes that say "I've got a bee in my bonnet and while I've said I'm looking for information, I'm really looking for affirmation".

Greenhill is your rule of thumb. There's a Greenhill Corollary for Boolits that says something to the effect of,"Generally speaking, cast boolits the same weight as jacketed will be slightly shorter, will stabilize at a slightly lower twist rate and will do better at lower velocity." Again, that's a rule of thumb, not a commandment.

Same weight, similar bearing surface, decent lube, a cast boolit of the same weight as a jacketed one will be somewhat faster and somewhat lower pressure. Skidding and smearing were discussed above and high velocity/ fast twist will often get you there. Another rule of thumb: heavy for caliber boolits seated close to or just off the rifling and pushed at a more sedate pace than the same bullet weight wearing a jacket will almost always do better than a smaller, faster boolit in the same caliber and rifle.

So, if you're building a rifle and want to shoot long for caliber jbullets from it, pick the fast twist and when you want shoot boolits with it, go big and slow. If cast is your game, back off a little on twist and shoot shorter jbullets. The bigger question is in throat design...

Now several people are going to come along and tell us how well their pet 85 grs boolit hard cast, under bore, and lubed with PAM does in their 257 Weatherby Magnum at 3100 fps and all these general rules of thumb are rubbish. That's fine.

[MBTcustom]

Twist can be underdone and overdone. Overdone meaning, more than needed to stabilize the projectile. But I do not believe a projectile can be over stabilized.

Right. Obviously, the 30-06 in a 10 twist is over stabilized by a pretty good margin.

[beagle]

Goodsteel......you done opened a can of worms here. Cast and jacketed are two different cases as we're all aware of.

Jacketed bullets are more uniform internally than cast and can withstand more velocity. We take that as a given.

With the Greenhill formulas floating around (and there are many), there are three variables that we can do anything about: bullet diameter, bullet length and velocity. A lot of sins can be overcome with velocity but here with cast bullets, we encounter skidding when we go too fast.

One winter, Felix and I messed around all winter shipping bullets back and forth between Arkansas and Kentucky and playing with twist rates, velocities and different length bullets in the .44 Magnum.

I had a Marlin M1894 1:38 and it wouldn't shoot cast worth sour grapes.....especially 300+ grain bullets. I sent it off and had a Douglas 1-20" twist barrel installed. Now, it shot 275-320 grain bullets but not lighter. Finally, I bought a Winchester Legacy M94 with a 1:26 twist and it shot the 240 grain Keiths just fine and the big bullets with acceptable accuracy so I quit while I was ahead.

From this experiment and our models with all bullets tried, we concluded that the ideal twist for a .44 Mag was 1-25 and a fraction based on the Greenhill version we were using and our range results showed us that we were on line.

The 1-20 twist was definitely over stabilizing the lighter bullets and this is the question I think we're talking about.

At this point in time one of the old members (Petey)was experimenting with impact coating cast bullets with moly and using no lube. I was looking at his rejects and he was getting voids in about 75% of his bullets. These were internal voids that weren't visible until after the tumbling operation for the moly coating.

Felix and I figured that this was the cause of inaccuracy in over stabilized bullets.

Yes, if the bullets were perfect, accuracy would be there even if over stabilized. If not, the over stabilization caused the void to unbalance the bullet and cause wild gyrations at over stabilization and inaccuracy on the terminal end.

I was really amazed at the number of voids in his and some .30 bullets I cast for him to coat that I thought were perfect. I mean on the ogive, base, in the bands and on the front driving band as well. What we thing are perfect bullets....aren't./beagle

[bnelson06]

My thought is that this is going to get interesting and I will be following closely :)

[MBTcustom]

I want to be respectful but you're sending out those vibes that say "I've got a bee in my bonnet and while I've said I'm looking for information, I'm really looking for affirmation".



Not particularly, and I take no offence to candid opinion. I apologize if I came across that way.
The thing is, I know how to recommend a twist rate for jacketed bullets, and I build rifles for that purpose. It's all very easy and well documented. 30 caliber builds are 10, 11.25, or 12 twist every single time. Until I build for a boolit shooter LOL!
Then we start talking about 12 14 and 16 twists. Nobody wants the ten.
It just set me to thinking about what's really going on, and lot's of you fellers have been doing this much longer than me.
Fast twist is hard on cast, we all know that. Not impossible, but harder.
I'm just sitting here stroking my chin and thinking
faster is better. It's always better, right?
Hmmmmm. Not with cast.
Why?
Well it could be two things. Either there is something inherently wrong with a cast lead projectile that makes it pee on it's leg when you spin it very fast, or the boolit is getting shredded by the rifling as it's slammed in there. I personally think it's the latter, but I have no proof whatsoever.
I've been devising plans to test the effect of rifling of varying twists on the same boolit fired from the same action but with different twist barrels, but the problem I have is catching the projectiles as they exit the barrel, and doing so in a way that's gentle enough to not damage them so that they can be observed under magnification etc etc etc.
Not an easy thing, especially when here in Arkansas we have mud.....not snow.
I just wanted to hear know if anybody else noticed that according to the calculators, jacketed bullet rifles should be able to run perfectly fine at cast boolit twist rates. and in fact cast boolits should be able to run at jacketed bullet speeds except for the engraving problem.

So does twist rate really not matter as much as I thought it did in the grand scheme of things? Are "problems" that I attributed to twist rate, actually more of a barrel harmonics issue?
I'm questioning the information that I have been fed and accepted as gospel, and cast boolits is just the place to engage in that sort of activity.
No hidden agenda. Just thinking about contradictory information that I have seen last year. Or maybe it wasn't contradictory and it was just my perception, but it lead me to question something that I have taken as gospel and that's usually a good thing.

[johnson1942]

speed or feet per sec. is the answer.

[MBTcustom]

I bet a jacketed bullet, of a proper design, will shoot quite well at 2000 fps in a 10 twist barrel. Would I use a 190 gr HPBT? Nope. A 150 flat base should work.

I don't see twist rate and jacketed as being related as much to velocity as it is bullet length. In Highpower a guy shootig just reduced course matches with an AR is fine with a 9 twist and 60 HP bullets. Try that barrel at a full course match and he is screwed at 600 because he can't use 80 gr bullets due to an overly slow twist.

I think much of the issue with cast at higher velocity and with faster twist barrels is more an issue of lack of experimentation than anything. I am sure that if one of the bullet manufacturers decided to get involved and swage or otherwise form very consistent bullets that they would find an answer. They have the money to spend to make it work, we don't.

I think much of the contradictory info you have seen is based as much on ego as "science". People get ideas in their head and dig in their heels, it get tough to overcome the mental inertia they develop.

I would love an open, spirited discussion on shooting cast at a variety of velocities and in a variety of twist rate barrels. Problem is to keep the facts in and egos out. Not gonna happen. We are all the worse for it.

Great concepts Tim, it is the reality that bites us in the butt.

I think you've got the right of it.
Still think it's worth a shot. After everything that I was taught, told, observed, and studied over the last few months, I really believe I have an open mind on the subject. All I know is that there is very wrong info out there and it's being taught mainstream. Which pieces are superstitious BS, and which are the real deal? Still trying to figure that out.

[geargnasher]

Overstabilization is rubbish. Overspinning a defective projectile, of ANY flavor, will cause large group dispersions. The moot concept of "overstabilization" and "spinning a defective projectile beyond it's 'RPM Threshold'" are two very different scenarios. So you either compromise twist rate and/or velocity to match your projectile quality, or fix the quality issues and shoot them however fast you like. Cast have weaker skins than jacketed and require special attention to the engraving portion of the firing cycle. Beyond that, there is very little consideration needed vs. jacketed as far as the rest of the trip through the gun and to the target goes.

Nobody wants a custom barrel in 10-twist because they don't know how to make, load, or launch the boolits correctly, and instead blame "overstabilization" or (the true cause) boolits that are defective in flight (defective for a multitude of reasons), and they then change barrels to a slower twist and/or velocity to compensate. A heavy cast boolit needs the same amount (about) of minimum rotational velocity as an equal BC jacketed one does. Yes, you can cheat some and run the ragged edge of barely stable, but that's not very reliable, especially way downrange where the velocity is falling off fast.

So, Tim, I'm glad you finally are starting to get an inkling of WHY it is that some of us laugh so hard when a 16" twist .30-'06 barrel is mentioned for shooting high velocity. Truth is, you NEED a 12 at least with 170-ish max bullets, and really could do with an 11. For 200-grainers, you NEED a ten-twist. Why do you think the .300 AAC guys are going to an 8-twist with 240-grain bullets even for subsonic loads?

The RPM threshold theory only applies to lousy boolits. Lousy how they're made, or lousy how they're launched, or both. Like John observed, you can spin a light boolit faster than necessary and experience negative effects from the extra spin due to boolit defects, and that could be considered 'overstabilization', but isn't really. It's simply that the RPM threshold of that system was exceeded by the extra, unnecessary spin. To my knowledge, there is no such thing as "overstabilizing" a true projectile. There IS such thing, however as UNDERstabilizing a projectile.

Gear

[Love Life]

A) Fat Lady was Sub MOA at all distances, and half MOA most of the time depending on how many smokes I had or coffee I drank between shot strings.
B) Fat Lady with the 1 in 7.5 shredded the 68 gr FBHP Match bullets when I juiced it with max charges
C) You need a solid test bed to figure this out...which means somebody needs to open the wallet. What good does it do to get info on this from people who are using different alloys, pots, moulds? People who may have poor or amazing loading techniques? People who may cast poor or amazing bullets (on the outside)? None. Look at your paper patch guys who are swaging and patching. I'd also peek into the BPCR world as they shoot far and accurately. Of course they aren't shooting barn burners...

With jacketed, you can say that length is the important factor...along with how much juice you put behind it.

It has been mentioned several times about the issues with internal voids. I would start with the elimination of that variable and move on from there. Until you can eliminate the issue of internal voids, it'll all be for naught and you'll pull your hair out.

If one person swaged lead (or agreed upon alloy) bullets for ALL in the research to shoot, then that would help immensely.

I would start here:
◦Ask a Question
◦Do Background Research
◦Construct a Hypothesis
◦Test Your Hypothesis by Doing an Experiment
◦Analyze Your Data and Draw a Conclusion
◦Communicate Your Results

Make one thing as consistent as possible (the bullet) to use as your control. Then start attacking the variables.

[geargnasher]

That's been done on an individual basis, LL. The problem is that very, very few believe the results or care enough to learn how to do it for themselves. It is far easier to attack than it is to learn, and most people are incapable of effectively following the process you outlined above on their own. Finding the solution to THAT problem is the real challenge that is rarely overcome on this board. I have done it to some extent with regard to high-velocity cast shooting, and proven to myself who is right about what here and who/what to ignore. Until the majority of the can't-dos on this board get an open mind, no cooperative learning will take place on this subject, only fighting. The can-dos are done fighting over it, and pretty much done sharing publicly until this situation changes. It's funny that when I was studying to be an engineer, they never mentioned how the number-one obstacle to progress isn't some sort challenge that a scientific mind has been trained to meet and defeat, it is something else that the scientist is woefully ill-equipped to handle: .......... it's called politics.

Gear

[AlaskanGuy]

I would think that the the faster the twist, the more it digs into the fps.... So wouldn't that mean that you would have to push harder to get the same fps in something that has a faster twist?

[Mk42gunner]

I do not know the answer, but I do have a few comments/ ideas/ questions.

-IIRC the Greenhill formula was originally worked out for either artillery or Naval gunfire, not small arms. It has just been adjusted a bit to sort of work. I can remember different sources using 150 or 180 for constants.

-The ten inch twist for the .30-06 came about because the Army decided on a ten inch twist for the 220 gr Krag projectile @ ~2000fps. When they came up with the .30-03 they used the same projectile at about 23-2400fps. When they went with the 150, they shortened and rechambered the barrels by one thread, to save money.

I can't be the only one that read of the lot of 03 Springfield's that showed better than average accuracy; which was traced to a rifling machine cutting a slower twist, (1:13" runs through my mind). The rifles were rebarreled with 1:10 and the others destroyed.

The 1:10 stayed in the Gov't .30 caliber rifles all the way through the M1 Garand; not sure of the Johnson, but I bet it was 1:10 too. It wasn't until the M-14 and 7.62mm NATO came along that they went to 1:12 twist.

-The talk of imperfect cast boolits has merit. Does anyone have access to one of the Juenke bullet testers? From what I have read they can find even slight differences in jacketed match bullets such as Berger and SMK. Might be worth checking into.

-And as Gear said:

Overstabilization is rubbish. Overspinning a defective projectile, of ANY flavor, will cause large group dispersions. The moot concept of "overstabilization" and "spinning a defective projectile beyond it's 'RPM Threshold'" are two very different scenarios. So you either compromise twist rate and/or velocity to match your projectile quality, or fix the quality issues and shoot them however fast you like. Cast have weaker skins than jacketed and require special attention to the engraving portion of the firing cycle. Beyond that, there is very little consideration needed vs. jacketed as far as the rest of the trip through the gun and to the target goes.

I will add that you can overspin jacketed bullets, I have seen it using M195 and M855 in the same rifles.

Robert

[MBTcustom]

I do not know the answer, but I do have a few comments/ ideas/ questions.

-IIRC the Greenhill formula was originally worked out for either artillery or Naval gunfire, not small arms. It has just been adjusted a bit to sort of work. I can remember different sources using 150 or 180 for constants.

-The ten inch twist for the .30-06 came about because the Army decided on a ten inch twist for the 220 gr Krag projectile @ ~2000fps. When they came up with the .30-03 they used the same projectile at about 23-2400fps. When they went with the 150, they shortened and rechambered the barrels by one thread, to save money.

I can't be the only one that read of the lot of 03 Springfield's that showed better than average accuracy; which was traced to a rifling machine cutting a slower twist, (1:13" runs through my mind). The rifles were rebarreled with 1:10 and the others destroyed.

The 1:10 stayed in the Gov't .30 caliber rifles all the way through the M1 Garand; not sure of the Johnson, but I bet it was 1:10 too. It wasn't until the M-14 and 7.62mm NATO came along that they went to 1:12 twist.

-The talk of imperfect cast boolits has merit. Does anyone have access to one of the Juenke bullet testers? From what I have read they can find even slight differences in jacketed match bullets such as Berger and SMK. Might be worth checking into.

-And as Gear said:


I will add that you can overspin jacketed bullets, I have seen it using M195 and M855 in the same rifles.

Robert

Indeed! Larry Gibson made mention of that very piece of history on the phone to me, and that appears to be fact.

The guys shooting lighter 150 grain boolits ask for 10 twist, but that is still a touch too fast. Seems that for jacketed, running at 2600-2800 FPS with 168-175 grain bullets, that 11.25 twist is the hells bells.

[MBTcustom]

Barrel twist is a variable I have control over Brad.
I care very much about chamber design, boolit quality and fit, precision of the loads etc.
A brief glance at the stickies that I have written will prove that definitively (at least that I care, not necessarily that I am right)
In this thread, I am exploring twist rates as they pertain to cast lead boolits that are assumed to have been cast, fit, and loaded perfectly.
I'm not missing the forest for the trees. I'm systematically considering every factor......obviously, and I am drawing conclusions.......in public.

Just trying to further the general understanding of cast boolits and bring us to a point that we are considering things that most take for granted, or just work around.

Now granted, barrel twist is a muddy soup and the science vs. superstition definitly seems lop sided towards the ethereal rather than the real.

As I have mentioned on the phone to you, I am looking to devise a few controlled tests using different twist barrels with that being the only differing factor. I want to know how this stuff works.
I have many theories, and opinions, but my thoughts are no more grounded in reality that anybody elses. It's theory based on loose pieces of disorganized data. I want to fix this, but I'm not made of money nor time, so I'm hoping that through this discussion, I can devise a few tests that will render a few pieces of better informed data.
Heck, it's all for fun. This is my hobby, slightly different than my vocation.

[243winxb]

http://www.bergerbullets.com/litz/TwistRuleAltWP.php
Since the onset of BC
variations seems to be consistently at or below Sg =
1.25, keeping the predicted stability above Sg = 1.30
is probably ample margin for error.
One might be tempted to try and design a rifle and
bullet combination to realize the increased BC of the
sweet spot observed near Sg = 1.23. The authors
think this is a bad plan and unworkable approach.
Even if the muzzle velocity can be held sufficiently
constant, Sg will change with environmental
conditions and shift the Sg out of the sweet spot. In
addition, the larger shot to shot variations in drag will
negatively impact long range accuracy and more
than erase the marginal gains from an average
increase in ballistic coefficient. http://arxiv.org/ftp/arxiv/papers/1309/1309.5039.pdf

[MBTcustom]

http://www.bergerbullets.com/litz/TwistRuleAltWP.php http://arxiv.org/ftp/arxiv/papers/1309/1309.5039.pdf

Great link 243winxb!

Look at what is written there:

Bullet companies usually publish a minimum
recommended twist rate, usually a twist that will
ensure bullet stability under the most dense
atmospheric conditions a hunter or recreational
shooter is likely to encounter, with some margin of
error so that no shooter is likely to ever report
evidence of bullet tumbling as long as the minimum
twist rate is used.
It seems reasonable to assume that our cast lead boolits are much more in need of the stabilizing benefits of faster, not slower twist rates!
Compared to a SMK, a cast lead boolit looks like a flying sack of potatoes no matter how well it was cast.

We are less aerodynamic. We have less BC. We have less SG. We need twist (theoretically).

If I could rewrite the way things are done, it would almost seem that highly aerodynamic jacketed bullets should be spun slower, and our boolits would be the ones getting the faster twists.
In the words of Spok "this **** aint logical".

It almost seems like we have thrown physics out the window because it's hard to get a boolit out of a rifled barrel unharmed eh?

[geargnasher]

No need to reinvent the wheel, Tim. Use existing data for the BC and projectile weight to determine minimum twist rate for velocity and distance desired, add a margin for variables, and accomplish the rest at the reloading bench. This has all been done before. What HASN'T been done is a comprehensive explanation of how to do this last part, the part at the reloading bench, which is by far the MOST important factor to achieving accuracy at high velocity with cast in any rifle.

Gear

[MBTcustom]

No need to reinvent the wheel, Tim. Use existing data for the BC and projectile weight to determine minimum twist rate for velocity and distance desired, add a margin for variables, and accomplish the rest at the reloading bench. This has all been done before. What HASN'T been done is a comprehensive explanation of how to do this last part, the part at the reloading bench, which is by far the MOST important factor to achieving accuracy at high velocity with cast in any rifle.

Gear

I hear ya Ian.
But I don't think that lots of people here are thinking about such things, and I wanted to give food for thought. Well, and I was hoping I might learn something in the process as well.
Muzzle not the ox don'tcha know.
If we can have a 40 page thread on thread killers or sarcasm font's, surely we can discuss twist rates for a minute eh?

[Whiterabbit]

No need to reinvent the wheel, Tim. Use existing data for the BC and projectile weight to determine minimum twist rate for velocity and distance desired, add a margin for variables, and accomplish the rest at the reloading bench. This has all been done before. What HASN'T been done is a comprehensive explanation of how to do this last part, the part at the reloading bench, which is by far the MOST important factor to achieving accuracy at high velocity with cast in any rifle.

Gear

What equation to use? Surely not greenhill? I can plug that in for 45/70 and get stability numbers in the 6+ or even double digits when supposedly 1.5 or less is best?

[MT Gianni]

While you can control the twist Tim, you cannot control the different alloys, 150 F swings in pot temps, lack of regular fluxing, dipper vs bottom pour, quenched vs tossed on a towel, improperly closed molds, etc. You cannot control the out of round sizer dies, dirty molds, voids visible or internal and our of round loading dies/press's and process's that make up much of our board. Far too many want to know what is the cheapest mold, lubing process and dies so I can shoot cheap lead with the same accuracy as my 5.56 match bullets in my existing gun. We can control twist but not what twist does to improper boolits as it will effect them in different ways. Thanks for making me think tho, I do know that at 59 & 5/6 my eyes best days are in the past.
I think too much is made of speed in the shooting sports and not enough of range estimation, holdover and sighting techniques. I know I don't need 3300 fps to kill a ground squirrel but that hydro-static shock is impressive.

[Larry Gibson]

geargnasher is absolutely correct with; " Overstabilization is rubbish. Overspinning a defective projectile, of ANY flavor, will cause large group dispersions. The moot concept of "overstabilization" and "spinning a defective projectile beyond it's 'RPM Threshold'" are two very different scenarios."

The twist required for proper stabilization for best accuracy (each length of bullet will have an "ideal" twist rate for best accuracy) has absolutely nothing to do with the adverse affect RPM has on any imbalanced bullet. An imbalanced bullet may be horribly inaccurate yet fully stabilized. As I've stated numerous times before; the RPM threshold of cast bullets has nothing to do with stabilization of the bullet in flight.

Ideally for any bullet of any flavor the minimal twist required for full stabilization will produce the best accuracy for that bullet all other things being equal. The reason being is the adverse affect of any imbalance will be minimized by the minimal RPM produced. Hence the reason for the 13 and 14" twist in Palma rifles which were originally intended for use with 7.62 NATO ball ammunition. The bullets of such ball ammunition was and is not noted for their match qualities. The minimal twist required for stabilization of the 145 - 155 gr bullets at the higher velocities the 27 - 30" barrels offered much lowered the RPM which minimized the adverse effect the imbalances in the M80 bullets had on accuracy, especially since the targets were 800, 900 and 1000 yards away.

Larry Gibson

[Pb2au]

It's funny that when I was studying to be an engineer, they never mentioned how the number-one obstacle to progress isn't some sort challenge that a scientific mind has been trained to meet and defeat, it is something else that the scientist is woefully ill-equipped to handle: .......... it's called politics.

Gear

That Sir, is a sad true story.
The engineer I have worked with for the last 8 years told me the same thing in a different way.
"Those that will benefit the most from change in a manufacturing process will be the ones that oppose it the most."
That has stuck with me a very long time. For the life of me, I do not understand when I read something here, like "hey, I just shot an awesome group with my rifle, at 2700 fps, here is the picture of the group", it turns into a blood bath. I can understand why folks get tired of rocks being thrown at them.

geargnasher for one, and others I have read here always come back again, and again to one single truth. (as I interpret it mind you).
It is a process quality issue. To start walking the path of higher velocities with a cast lead projectile, everything you do up to point where the finished cartridge is in battery and the trigger is pulled, has to be the best work you can do. Best alloy, best design of projectile, best sizing, best loading practice, best load development. The end game is to arrive to this point of quality, you have to identify and control your variables.
The lead projectile simply in my mind isn't as forgiving as a jacketed one. It is a materials issue.(again, in my mind) So those that walk the path gain this understanding and dial down the tolerances on everything else to account for it.
Am I dialed down this tight on my current Mauser project, or my Krag project, no. Not yet....but, this is how we learn. We learn by doing and paying attention to the details.
So, the conclusion to my long winded ramble is that I see your focus on the twist rate as an important key to this, and it will tease out the other details that create the whole picture. That is to say, it will tease them out for those of us that really read the details.

Tim, this is an excellent experience. I have re-read this thread a few times now as it grows and continue to make notes. Thank you to the contributors.

[MBTcustom]

Ok Larry, im with you so far with the Palma rifle twists etc, but how does it work when we take a heavier, longer and less precise projectile like a boolit, and we shoot it slower and stabilize it less??

I understand damage to the boolit on engraving, blah blah blah, but assuming you could get the boolit out of the barrel undamaged like with paper patch etc, why would you shoot and spin it slower if it's longer ?
Seems that if you have a damaged boolit, it would be counter intuitive to take stability from it by dropping it's speed and RPM to a place that it never would have run correctly in the first place, to apologize for shooting a damaged projectile in the first place.

That just rubs my brain the wrong way for some reason.

Seems that if we build the perfect, concentric, well fitting load, we should either twist it correctly or find a different projectile that fit's our parameters better, or find a way to launch it without damage.

This is all purely theoretical, and I'm assuming there is a way to accomplish launching an undamaged boolit. I have heard claims from people who claim to have done it, and I don't doubt it for a second, being the type of guy that takes a man at his word till he proves himself a liar.
I have never seen, nor experienced this myself personally (at least not to my knowledge).
I'm just saying that if it were possible why would we spin a boolit slower?

[MtGun44]

I have access to a Juenke machine and have tested 2nds of 175 Mkings in some significant quantites.

It is my understanding that it makes no difference how fast you spin a bullet once you have gotten
enough speed to stabilize it gyroscopically - until it blows up from rotational forces. I have actually
blown up some small .22 cal bullets by spinning them too fast. This presumes a PERFECTLY
balanced bullet/boolit.

The real world situation is that ALL bullets/boolits have some degree of imbalance. The development
and use of the Juenke machine has helped bullet makers like Sierra get their products dramatically
better as to balance. Another driving factor was the military developing the (IIRC) M856 Tracer round.
This is a 1200 yd trace 5.56 NATO round and the bullet is extremely long - under arctic conditions it
required a 7 inch twist barrel to stabilize, so the Army standardized on that twist. Most ammo shot
thru the military guns is 62 gr M855, and they need to be well enough balanced to meet accy requirements,
so the goalpost is moved - as far as how good a "normal production bullet" has to be balanced- SINCE THEY
ARE GOING TO BE SPUN WAY FASTER THAN IS "NECESSARY".

Us civilians started getting 7 inch twist barrels and shooting 55 FMJBT M193 and even 50 gr flat base boolits - at
amazingly high rotational speeds. Some varmint bullets blow up, but we EXPECT THE AMMO TO SHOOT WELL,
EVEN WHEN SPUN "TOO FAST" and this is another factor driving "normal production bullets" standard of
balance way up - and the Jeunke machine has allowed bullet makers to measure their quality, along with
range testing in "too fast" twist barrels.

Once we had 80 gr VLDs in .224 diam - people started wanting scaled up versions for .30 cal - and guess
what? They needed fast as heck twist barrels, and then they would be upset if that fast twist barrel
scatters 168 MKs all over the target - another factor driving up the quality of bullets - as far as balance
is concerned. There are now lots of rifles being made with "too fast" twist, so the bullet makers need to
balance their jbullets well enough to avoid inaccuracy - again moving the goalposts on balance quality.

The flies in the ointment is three things: 1) boolits are relatively lower quality (well mine are - maybe yours
are perfect) and can't stand to be spun too fast because they will wobble and not shoot as accurately.
2) boolits are comparatively weak structurally and can blow up from rotational forces at spin rates that
jbullets can survive.
3) boolits can't stand the mechanical shock of spinning up super quickly in fast twist rifling and can strip,
or skid and get totally messed up.

These three things mean that we have to keep our boolits running JUST fast enough rotational rate to stabilize,
but not to fast because of relatively lower quality of balance, rotational structural strength and ability to grab
the rifling when launched. Jbullets - with modern quality levels - can be spun as fast as you want until they
blow up and are still pretty accurate. The old "overstabilized" (IMO) was just a way of saying "spun to fast
for an out of balance bullet". "Overstabilized" doesn't seem to happen very much these days with jbullets -
because they are far better balanced bullets than was standard 30-40 years ago.

Bill

[geargnasher]

geargnasher is absolutely correct with; " Overstabilization is rubbish. Overspinning a defective projectile, of ANY flavor, will cause large group dispersions. The moot concept of "overstabilization" and "spinning a defective projectile beyond it's 'RPM Threshold'" are two very different scenarios."

The twist required for proper stabilization for best accuracy (each length of bullet will have an "ideal" twist rate for best accuracy) has absolutely nothing to do with the adverse affect RPM has on any imbalanced bullet. An imbalanced bullet may be horribly inaccurate yet fully stabilized. As I've stated numerous times before; the RPM threshold of cast bullets has nothing to do with stabilization of the bullet in flight.

Ideally for any bullet of any flavor the minimal twist required for full stabilization will produce the best accuracy for that bullet all other things being equal. The reason being is the adverse affect of any imbalance will be minimized by the minimal RPM produced. Hence the reason for the 13 and 14" twist in Palma rifles which were originally intended for use with 7.62 NATO ball ammunition. The bullets of such ball ammunition was and is not noted for their match qualities. The minimal twist required for stabilization of the 145 - 155 gr bullets at the higher velocities the 27 - 30" barrels offered much lowered the RPM which minimized the adverse effect the imbalances in the M80 bullets had on accuracy, especially since the targets were 800, 900 and 1000 yards away.

Larry Gibson

Yes, exactly. Going at the minimum twist required for the intended use (range, weight, bc, etc) buys a little insurance against balance problems with bullets of any flavor. The only issue with this is that, when optimizing twist for the desired application, there is obviously a natural performance and option trade-off with any bullet type or design that falls too far left or right of center.

When extending the twist rate of a barrel to reduce the effect of imperfections in our cast boolits at higher velocities, there is a practical limit to boolit weight. There one has to make a decision on weight, maximum distance, and velocity range for a particular application. The optimum stabilization rpm still applies the same to cast or jacketed with a given twist. If one wants the option of shooting 220-grain cast boolits in their '06, but selects a 14" twist rate optimized for 150-grain or lighter projectiles, there will be stability problems regardless of how well the heavier boolit is launched.

As you pointed out, stability and imbalance (imbalance for whatever reason), are two different animals entirely. If your cast boolits are correct for the twist and velocity but still don't group well, then the problem lies with the balance quality and launch of the boolit, and after that, fine-tuning to the harmonics. All of those things have to be right to get tiny groups.

Gear

[MBTcustom]

Solid discussion fellers! Good stuff, and great info.

So if I understand this right, as long as the RPM's are enough to soundly stabilize the projectile, you're in like Flynn no matter what speed you are shooting at. It falls to harmonic nodes from there.

RPM does in fact have a detrimental effect on imperfect boolits. Since boolits have inherent imperfections built into the process itself, RPM's should be kept to a minimum in order to give the best results.

Jacketed projectiles are able to survive super fast twists accurately because of their superior accuracy of manufacture, not necessarily the hardness of the jacket. Therefore, attention to detail and precision with our cast lead boolits becomes paramount to shooting fast twist, regardless of weather the boolit is damaged in the throat or not. If you got janky boolits, you're gonna have janky groups.

Interesting how a discussion on ideal twist seems to bring all areas of our discipline together.

[geargnasher]

Solid discussion fellers! Good stuff, and great info.

So if I understand this right, as long as the RPM's are enough to soundly stabilize the projectile, you're in like Flynn no matter what speed you are shooting at. Within reason, yes. It falls to harmonic nodes from there. No. There's the big elephant in the room to consider next, THEN the much more minor vibration tuning which is easily managed through a number of fine tuning techniques.

RPM does in fact have a detrimental effect on imperfect boolits. Since boolits have inherent imperfections built into the process itself, RPM's should be kept to a minimum in order to give the best results. That depends on the severity of you "inherent imperfections" and the purpose of the rifle/load. Versatility is compromised if you focus on the minimum and not on the elephant. Mastering the elephant will give you a LOT more options with a rifle.

Jacketed projectiles are able to survive super fast twists accurately because of their superior accuracy of manufacture, not necessarily the hardness of the jacket. No, it's the elephant again. Read Bill's post again. Therefore, attention to detail and precision with our cast lead boolits becomes paramount to shooting fast twist, regardless of weather the boolit is damaged in the throat or not. If you got janky boolits, you're gonna have janky groups. If the boolit is torn up at launch, or even under hard acceleration, it doesn't matter how good it was when it was ready to fire. Likewise, if you achieve a good launch, but the boolit has an internal balance defect or aerodynamic flaw, it won't shoot straight either past whatever it's rpm threshold happens to be. Clear as mud?

Interesting how a discussion on ideal twist seems to bring all areas of our discipline together.

Nobody's talking about the elephant, Tim, which is the BIG deal with getting cast to shoot. The elephant's name is "Launch". But since that doesn't deal with twist rate directly, is a better subject for another thread that I'm afraid won't get much meaningful traffic here.

Gear

[nekshot]

starting to think the savage recievers are perfect for booliteers. Get a barrel/twist for each boolit in its weight class. 3 differant barrels should cover my needs!

[MBTcustom]

I'm really glad I started this thread. I think you could be right Brad. I've been thinking of twist the wrong way......I think. I'm going to reread this a couple more times and sleep on it, but it sure is looking like I need to change my thinking.
I think I was right about the lower end of the twist, ie. there's a point where you're just not stabilizing the boolit properly, but my thinking that there is a narrow range of twist that a boolit will like to run is starting to smell a little funky......like BS.
Oh well, this is why I'm still here.

[MBTcustom]

Nobody's talking about the elephant, Tim, which is the BIG deal with getting cast to shoot. The elephant's name is "Launch". But since that doesn't deal with twist rate directly, is a better subject for another thread that I'm afraid won't get much meaningful traffic here.

Gear

Where would you like it? Care for a civil, moderated (as best I can) discussion on the subject?
Much like this one, but a different theme?

[geargnasher]

Where would you like it? Care for a civil, moderated (as best I can) discussion on the subject?
Much like this one, but a different theme?

No, I don't want a "discussion". I want what 45 2.1, Brad, and I asked for on the thread you closed. The only discussion allowed would bear directly on how to sort out specific problems we encounter at each part of the process of making the documentary. People who don't have real answers can sit still and watch and keep their keyboards to themselves and not derail the thread. No more "Well, I think this" or "I think that" blah blah blah. Just facts, like in Missouri. I believe we were told "no" by those in charge.

Gear

[Larry Gibson]

Nobody is going to convince me that all else being equal the twist rate difference between a 12 and 14 twist 30 cal barrel will be the single largest factor in group size at 100 yards.

The twist rate difference between a 14" and 12" barrel, all other things being equal, will be "the single largest factor in group size at 100 yards." if you plan on maintaining the same level of accuracy with cast bullets at 2600+ fps vs 2300 - 2400 fps.

If one is satisfied with just "accuracy" using cast bullets then one can get it with just about any bullet weight from 70 gr to 220+ gr in a .30-06 with a 10" twist. We know that because most do that all the time, at velocities from 800 to 1900 fps. However, if you want that same accuracy at velocities above 1900 fps then bullet design, casting, loading and "launching" as close to perfect cast bullets as we can possibly do becomes of paramount importance. The reason being is just above 1900 fps in a 10" twist barrel the RPM generates enough centrifugal force to adversely affect any imbalance in the bullet in flight. You can strive for cast bullet perfection and launch or you can slow the twist down to keep the RPM under 140,000.

Yes that requires a different barrel. But if building a cast bullet shooter why not consider the slowest twist that will properly stabilize the chosen cast bullet? Note here there is a difference between minimal stabilization and "stabilized" as far as twist rate goes. The idea that a slower twist some how limits you to just the one cast bullet and some how is not "versatile" is mistaken. I can still shoot 70 - 200 gr cast bullets with very good accuracy in a 14" twist .308W. The 160 gr 311466 is my bullet of choice for that rifle but an 18: twist would still stabilize that bullet at the 2600 fps I shoot it at. Thus the 14" twist keeps the 311466 under 140,000 RPM and stabilizes the heavier 311299 at 2400 fps quite well. If there is a "limitation" or non versatility it is with lighter weight bullets. A 122 gr 311465 can be pushed to 3000+ fps in that rifle. However, it also loses accuracy at just over 2700 fps. Why? because that is where it approaches 140,000 RPM and it is being accelerated very hard.

That is why I'm getting a 16" twist barrel of 26-28" length (very hard to find one available) for my own 30x57 for use with the 311466 or the LBT 30-160. I want to push 2800+ fps and need to keep the RPM under 140,000. Both of those bullets will be fully stabilized in the 16" twist BTW. No, it will not stabilize the 200 gr bullets but if one wants to dance one has to pay the band. In this case I have no need for any cast bullet over 160 gr as I have numerous 10 and 12" .30 caliber rifles to use those.

One does not buy a 22 Hornet to hunt everything from mice to grizzlies. It is specialized for a specific purpose. So is a slower twist cast bullet shooter. If "versatility was wanted then the concept/conundrum of the "all around" rifle cartridge would have been settled long ago.

Larry Gibson

[Larry Gibson]

Not buying it Larry. You are saying that bullet and load quality play second fiddle to twist rate in how well a bullet shoots. Nothing trumps load and bullet quality.............The rpm threshold isn't a threshold at all, it is a realm at which bullet and load quality rear up and demand to be heard.

I did not say that at all. Quite to the contrary I have repeatedly said in these conversations the trick to shooting cast bullets at HV is to launch as perfectly a balanced a cast bullet as possible. A perfectly cast and loaded cast bullet perfectly chambered does not guarantee a perfectly balanced bullet will come out the barrel (at "launch"), especially with the higher psi required for HV. The problem is with HV comes acceleration and the faster we accelerate a cast bullet the harder it becomes to keep the cast bullet perfectly balanced at launch.

The RPM threshold is not "determined by the SYSTEM". Everything that occurs before launch is internal ballistics and it is very important. It is there that the barrels twist will determine the RPM at a given velocity. The RPM threshold is the effect of centrifugal force on the bullet in flight. Centrifugal force is independent of internal ballistics and there is nothing we can do in the "SYSTEM" to change it as it does not occur there. The centrifugal force will act on any imbalance in the bullet (cast or jacketed) during flight. What we can do is influence the imbalances imparted to the cast bullet during casting, loading and acceleration. Thus at the RPM threshold the centrifugal force will cause the bullet to either go off on a tangent from the line of flight or to begin an increasing helical spiral around the line of flight. The degree of either depends on the imbalance and the amount of centrifugal force. In either case the stability of the bullet is not affected. That is during the external ballistics (the bullet in flight) and it is equally as important to understand. We must understand the cause and effect of each ballistic phase in order to succeed.

If we understand where the RPM threshold will most like appear and simply keep the RPM below that we negate the potential adverse affect of the centrifugal force when it reaches the threshold point. That can be done by keeping velocities low with a fast twist or by using a slower twist. In either case we are controlling the RPM which is what allows us the accuracy.

Larry Gibson

[Larry Gibson]

btroj

No, the RPM threshold is not a set limit. We've been through all of that before.

The RPM threshold is seen in jacketed bullets. It's why the Palma shooters when they had to use 7.62 NATO ball ammunition issued by the host nation went to 13 and 14" twist barrels. They did that to lesson the adverse affect the centrifugal force had on the not so well balanced military ball bullets. It is also seen with any long range shooter; they use the best match bullets which are extremely well made and balanced to begin with. Jacketed bullets also withstand acceleration far better than any cast bullet will. Back in the beginning of this discussion several years ago I purpose imbalanced some M118 bullets and shot them demonstrating to bass ackwards that the RPM threshold applied to jacketed bullets too. It does, it is just at a much higher RPM is all. Many times that is above the velocity capability of the bullet in the cartridge used.

Twist rate is indeed a major answer to shooting cast bullets with accuracy at higher velocity. The given the same cast bullet and components a 10" twist will lose accuracy before a 12" twist will and a 14" twist will maintain accuracy to a higher velocity than a 12" twist. This is easily proven with 10, 12 and 14" twist .30 cals. It is also easily proven with 9, 12 and 14" twist .22 cals. I have rifles of each in the same cartridge and prove it over and over again with different cast bullets and powders. If you are building a cast bullet rifle with HV in mind then it would be very prudent to consider the twist unless you are masochistic and prefer a 10" twist. However, if you already have a rifle it is what is and the choices of bullet design, fit, alloy and powder selection become paramount along with a couple other things.

The two phases of ballistics are definitely related but the are also separate. And no, twist rate is not the "whole answer". I never said it was. I have been shooting cast bullets in various twists for a long time. I am not talking theory but facts based on a lot of practical testing of accuracy, velocity and pressures. I am shooting cast bullets at 2600 fps with 1.5 moa accuracy (average) for 10 shots out to 300 yards using the .308W. It is not with a 10 or even a 12" twist barrel. My cast bullets (311466) are of a ternary alloy and are WQ'd. They run 26 - 28 BHN. They are GC'd and lubed with a NRA 50/50 lube or with Lar's 2500+. Bullet design, proper fit and a proper powder are also very necessary.

However, the topic of this thread is "Ideal twist rates" not how to shoot your 10" twist .30 cal at HV. I was discussing the topic, "ideal twist rate", and what twist is ideal. Apparently you're not?

Larry Gibson

[35 shooter]

Just wanted to say this has been a good thread guys. I picked up on a couple of things here i needed a reminder on. In fact i picked up on several things i've been kind of in a grey area on. I will also say i would love to see a discussion on launch with cast boolits too, as i've already found out the benefits of filling the case with a slower powder lately for a softer launch so to speak. Enjoyed reading this thread very much...Thanks.

[MBTcustom]

Brad, while I agree that twist rate is far from the most important factor, would you not say that for a given load with all it's tolerance stackup, that you could get faster with that load with a 16 twist than a 12 twist? Would the slower twist not take the pressure off a little bit?
What's the disadvantage? Why spin the livin "holy RPM theory batman!" out of it?

That's what I want to know, and my personal interest in this thread. Larry says 16 twist. You say 12. Why 12 and not 14? Why 16 and not 14? Why, in your opinion, must we stay as close to the 12 as possible?
It just seems to me that while shooting a 12 seems more versatile in theory, that the reality would be that the 12 twist is going to be a cruel taskmaster that will beat you to a pulp if you get off the path just a little bit, while the 16 twist would be more forgiving while insisting on speed. Like a stoned racecar driver "its all groovy maaaaan! Just go fast OK, and don't have a cow..." LOL!

I was asked about building a 30XCB by a very special client, and he mentioned that he was considering a 16 twist. I think I told him correctly that that would require him to shoot light boolits fast in order to get good results. had he said he was going for a 12 twist, I would have told him that would require him to shoot heavy boolits slowly in order to get good results. As it was, I told him that I thought that 14 was a good compromise.

[Larry Gibson]

Btroj

“So to demonstrate the threshold with jacketed you deformed some bullets. Does that not imply that this threshold has something to do with bullet quality? If a bullet needed to be imbalanced to show the effects then the effect on a good bullet must be quite minor.”

That is essentially correct. I induced imbalance into the jacketed bullets (they were of reasonable quality) which lowered the RPM threshold for that particular bullet to demonstrate the non linear effect when a bullet, even a jacketed bullet, exceeds the it’s RPM threshold.

Imbalances are affected by RPM in cast and jacketed bullets. Read post #42 by MtGun44 again. It is excellent and correctly addresses the subject. You might also read the article and look at the pictures about accuracy in bullets in Hornady manuals where the subject is also thoroughly discussed. The centrifugal force of the RPM acting upon the imbalances in the bullet in flight is why we shoot groups instead of all the bullets going into the same hole. There is one other reason but it’s affect is actually quite smaller than many think.

“My point is that when we determine a twist rate it is always better to go too fast than too slow. An I destabilized bullet will never be accurate yet an over stabilized bullet will show, at most, small accuracy disadvantages.”

Here again let us not confuse bullet stabilization with what occurs when a bullet exceeds the RPM threshold. Two completely different phenomenon.

Yes, a “better bullet” can handle RPMs better. As I’ve stated many times the trick to pushing the RPM threshold up is to get that bullet out of the barrel (launched) at HV still in “better” condition. The harder/faster we push a cast bullet the harder it is to do. Thus as Berger correctly states; “the faster spin amplifies inconsistencies in the bullet”. As much as we hate to admit our cast bullets are nowhere near as “better” in balance than a Berger bullet. As much as we try through different alloys, heat treating and now PCing a cast bullet will still not be able to withstand the acceleration w/o deforming that a jacketed bullet will, especially at HV.

The fact is the centrifugal force will always affect a cast bullet more and at a lower velocity/RPM because the cast bullet will probably never be as balanced in flight as any Berger jacketed bullet.

Larry Gibson

BTW; this thread has been informative and a pleasant discussion. I see no need for emotional derogatory insinuations now, do you? Had you read the many posts and even a thread I made/started regarding my Palma loads at 2600 fps you would have all the load detail. I have been very open about it or as they say theses days; "transparent". Also had you read my many recommendations on shooting cast .30 cal bullets at HV you would know I do not recommend 4895 with a Dacron nor do I use it in the 2600+ fps Palma loads. I recommend the slower burning powders such as the one I use in the .308W in the Palma rifle. Your comment is really uncalled for and unwarranted.

You seem to want to rehash the RPM threshold (even though you've come to grips with it's existence) or justify your choice for whatever twist you chose? This thread is about the "ideal twist". I do not espouse the 10, 12, 14 or even the 16" twist as "ideal" because which ever is "ideal" depends on the cast bullet we want to use and the velocity we want to use it at. I use all of them quite successfully and consider each as "ideal" for their intended purpose with certain cast bullets within certain velocity ranges. I do not think there is an "ideal" all around twist. Any of the above twists are going to be "ideal" within certain parameters which they all have. Some are more "versatile than others but they all have a fairly broad range of abilities with different weight cast bullets at different velocity ranges. None of them shoot all weights of cast bullets equally well at all velocities.

So with that in mind and the topic of this thread also in mind can we keep it pleasant?

[Larry Gibson]

Goodsteel

Back to the topic of this thread.

The “ideal twist” for jacketed or cast bullets is dependent on the design and length of the bullet, be it cast or jacketed. However, the term “ideal” is deceptive in that if we do not consider velocity then any twist rate can be “ideal”. For example; a 10” twist ’06. With that we can load a GC’d 118 gr FN at 800 fps and have excellent accuracy. Conversely we can load a 220 gr GC’d cast bullet down to the same 800 fps also with excellent accuracy. But what if we add an additional qualifier of velocity to “ideal”?

Let’s say we want linear accuracy to 300 yards of 1.5 moa or less (I believe some sort of accuracy was already a qualifier of “ideal”?) at 1950 fps? The 220 gr cast bullet will do that easily. However, the shorter and lighter weight 118 gr cast bullet will be very difficult to get there. The velocity will be easy for the lighter bullet but the accuracy will be difficult meet. The reason is the 220 gr bullet is stabilized at that velocity and the lighter, shorter 118 gr is over stabilized. (note; I am not talking the RPM threshold with this example but referencing stabilization) Thus we see the 10” twist is not “ideal” for the 118 gr bullet but probably is for the 220 gr bullet.

If we want a higher velocity then the RPM threshold also comes into play. If we were to have an 18” twist it would be “ideal” for the 118 gr bullet but not good at all for the 220 gr bullet. Thus we see if we are going to discuss an “ideal” twist a couple more parameters are needed.

As to the “versatility” of the 14 and 16” twists. A lot is made of that but in reality it is a moot point. If one is building a cast bullet shooter one needs to make a simple choice; do you want an “all around rifle" for any weight of cast bullet? Or, do you want a specialized rifle for a smaller range of cast bullets at higher velocity?

A 16” twist .30 cal 30x57 will fully stabilize (already done the math) a 190 gr 311334 at 2400 fps, the 30-180 MP at 2200 fps, a 311041 at 2200 fps, a 311466 at 1600 fps, an LBT 30-160 at 1500 fps and a 311465 at 1400 fps. The RPM threshold will probably be 2900+ fps. There is a lot of “versatility” there.

A 14” twist .30 cal 30x57 will fully stabilize (not only done the math but have shot said bullets in my .308W w/14” twist) the 311334 at 2250 fps, the 30-180 MP at 1850 fps, the 311041 at 1700 fps, the 311466 at 1550 fps, the LBT 30-160 at 1450 fps and the 311465 at 1050 fps. The RPM threshold is 2700 fps +/-. A lot of “versatility" there too!

Additionally the 311299 does ok in the 14" twist above 2400 fps. Certainly not "ideal" but ok. It does a lot better both accuracy wise and across a broader velocity spectrum in the 12" twist and may be considered "ideal" for that twist. Perhaps you see what I am getting at; there isn't really any "ideal twist" but in reality "ideal" bullets for a specific twist within a specific velocity range.

I have conducted several tests with different cast and jacketed bullets in .30 cal twists of 10, 12 and 14” and in .223s with twists of 9, 12 and 14”. By measuring the TOF/BC of the bullets (across 100 yards with the Oehler M43) at a given velocity we can compare the stability of the bullets (the higher the BC and shorter the TOF at a given velocity the more stable the bullet is in flight) that each twist imparts. I have related this several times and can again if you are interested. It is an ample demonstration that the “ideal” twist is more of a function of the design and length of the bullet used than anything else.

Larry Gibson

[Fluxed]

One good rule of thumb is that "just enough twist" is the right choice for a given bullet and velocity/load range. Its the well established standard in short range BR, and for good reason - decades of empirical data from millions of rounds fired under match conditions. Its been a thorough test of what works on the target and what does not.

I built a BR rifle in a short .308 (like a .30 BR with a long neck) many years ago with a 1-14 twist. It shot 170ish grain boolits very, very well. I could not get the consistency I wanted, but that was a boolit quality problem, not the fault of the rifle. My current .30BR chambered rifle is a 1-18 and shoots light jacketed bullets wonderfully. I've not shot it with lead though - I will have to try that when I get time.

If you're building a purpose built cast boolit rifle, then definitely pick a twist that is just enough and not a whole lot tighter. (i.e. - maximum accuracy at 100 yards with 150 gr. boolits, or 600 yards and 200 gr. boolits)

If you want to shoot a wide variety of projectiles you'll need to pick a twist that is enough for the boolits that require the most stabilization. This necessarily means that the lighter/shorter boolits will get more spin than they need. In that rifle, all boolits may not shoot as well as might be possible under optimum twist conditions for each boolit.

[missionary5155]

Greetings
Has anyone mentioned gain twist barrels ? To me that is the best there is to come by for us lead shooters. Sadly there are expensive and I understand why.
Then there is the actual rifling shape. Always seemed to me a good solid square edge would "dig into" or grip the boolit far better. That rifling edge the boolit is torqing against is of little help if it is not restaining the bullets twist but due to roundness or sloped less high to permit the boolit to "slip". Seems like that may be why our oversized diameter boolits shoot better. They are under pressure being squeezed into a small hole. By the time they get evened out to groove diameter thay are up to barrel RPM and all is well.
Maybe my problem is I like to have too many shooting sticks to rassle. Should probably sell off the half that are just iffy cast shooters and enjoy the rest of my time with those that really seem to perform. But I would get bored.. no more challenges.
Mike in Peru

[MT Gianni]

I've been reading this thread since it started yesterday morning, read it a few times now. Fascinating actually and I for one would love to keep this thread/topic going but would also dearly love for the other topic mentioned to finally get started. Chamber fit, launch, cutting a proper chamber for boolits, boolit style for proper chamber fit. I don't know if anyone has noticed but I think a record has been set here, 55 posts and no thread drift, no yelling or cussing. Perhaps this forum could work for such a topic.

Wishful thinking perhaps but at least keep this topic going. I'm all ears.

Rick

Rick, I believe the lack of thread drift is that it is hidden in Gunsmithing. Perhaps future discussions on this and similar could be hidden here as well.

[Larry Gibson]

So if the threshold has nothing to do with stability then what, precisely, does it mean?

As for our bullets being nowhere near as good as Berger or Sierra, I can guarantee mine aren't even close. No way, no how. Those guys make dang good bullets and no cast is that well made.

The RPM Threshold? if that's what you're asking about then I've explained it numerous times in other threads. I really don't want to go there (explanation of the RPM threshold) in this thread unless goodsteel gives the green light. Suffice to say I think the thread is mostly about the "ideal twist" being one that adequately stabilizes the bullet w/o "spin(ing) the livin "holy RPM theory batman!" out of it" as goodsteel put it.

If one is happy with numerous different cast bullets easily and accurately shot at 800 - 1900 fps out of his 10" twist .30 cal then that probably is "ideal" to him. If another is happy with the same but want s to easily reach into the 2300+ fps range with a couple of those cast bullets then the 12" twist is probably "ideal" for him. And if another wants to shoot various cast bullets from 1000 fps to 2600 fps with a couple of them easily and w/o too much trouble or agony then a 14" twist longer barrel is probably "ideal" for him.

Larry Gibson

[nekshot]

forgive me for butting in, but I do find this interesting and at time I think most of you are kinda agreeing on the same thing, your just coming at it from differant angles. Could a chart or grid be made for a say 30 cal. Boolits of 150 - 165 work at fps in given twist, 170- 190 work at fps in given twist, 200- 240 work at fps in given twist. Then we could go on to the hocus pocus of launching the boolit! Tell me to shut up if I am off the wall but I want to learn and at times this almost makes me sit upside down trying to figure you all out! The first time I read this I thought I needed some aspiran afterward!

[Larry Gibson]

Goodsteel

An interesting side note to consider is that the '06 has a 10" twist because that was what was used with the original 220 gr RN bullets in the 30-40 and the 30-03. When the change was made to the 150 gr M1906 cartridge there was no need to retool because the 10" twist worked ok. Pretty well actually but it was definitelyy known to be lacking in long range capability which is why in the '20s the military went to the 174 gr M1 bullet.

However, during the development of the 7.62 NATO cartridge the bullet weight was settled on 145 - 155 gr with it being a FMJBT. Considerable testing was done with it, the M1 bullet, the tracer bullet and the AP bullet. It was found the 12" twist was "ideal" for all of those bullets out to the expected max effective range of 600 - 1100 meters, depending on bullet. That has especially proven to be the case with BT bullets of 150 - 175 gr weight.

So the "why" and the "difference" between jacketed and cast bullets has more to do with the cast bullet not holding up as well at higher acceleration. The cast bullet just has larger imbalances than do jacketed bullets at the higher acceleration rates and those are accentuated much more at higher RPM of the faster twists. I have gotten a 155 - 160 gr cast to shoot very nicely in my 14" twist because I attenuate the RPM to a lower rate with the slower 14" twist. I do believe that same bullet can shoot just as well at 2700 - 2800+ fps and maybe even 2900+ fps in a 16" twist barrel of a minimum 26" length with the 30x57 or the '06. The reason is the bullet will be fully stabilized yet the RPM is kept below the RPM Threshold. That's why I am willing to put my $s where my mouth is if I can ever get such a barrel(?). I am unable to find one so I guess I'll have to just pick a maker and put my $s down and wait............:???:

Some may get wrapped around the axle over my choice for this based on "lack of versatility" but I think they are just arguing for the sake of just trying to prove me wrong or some other unknown point. I do not intend this to be a "versatile" or "all around rifle". I have plenty of other rifles that can handle the heavy bullets. This rifle is intended strictly for HV cast bullet shooting with the 155 - 160 gr 311466 or the LBT 30-160. This rifles purpose is to see if we can indeed shoot a .30 caliber cast bullet at that high of a velocity with excellent and linear accuracy to 400 - 500 and maybe even 600 yards. It's intended use is simply longer range hunting for coyote and possibly antelope. I have no intention of shooting lighter weight or heavier weight cast bullets.

If the 16" twist barrel does not work in the 30x57 or '06 to expectations then the barrel will be pulled and converted to a .32 H&R Contender Rifle barrel. That twist will be excellent for 70 - 118g cast bullets at 1000 - 1400 fps in that cartridge. In that case I also will be happy with my "versatile 14" twist .30W Palma rifle:drinks:

Larry Gibson

[Larry Gibson]

forgive me for butting in, but I do find this interesting and at time I think most of you are kinda agreeing on the same thing, your just coming at it from differant angles. Could a chart or grid be made for a say 30 cal. Boolits of 150 - 165 work at fps in given twist, 170- 190 work at fps in given twist, 200- 240 work at fps in given twist. Then we could go on to the hocus pocus of launching the boolit! Tell me to shut up if I am off the wall but I want to learn and at times this almost makes me sit upside down trying to figure you all out! The first time I read this I thought I needed some aspiran afterward!

That could be done but the length of the bullet is needed for stabilization computation. Also an important consideration is the bullet design for the given cartridge. Some designs are just not suitable to really HV if that's what's interesting to someone.

Larry Gibson

[nekshot]

Larry, I am slowly understanding the length thing has a big factor in this also. I guess I think it would be helpful for a chart that maybe would say this specific boolit works best in these given speeds and this boolit works best at so and so. Fortunatly when I started casting I knew to stay slow but I didn't know why. Maybe its wishful thinking but I would love to get all of this threads info in a pratical chart for a newbie or a somebody like me! Keep talking fellas you all have a lot to give,I'm listening!

[UBER7MM]

I've always wondered about the old Model 94 Winchesters. The .30-30 Winchester = 1 in 12" and the .32 Win. Spec. = 1 in 16". All other things being the equal for this example, there isn't that much difference in the bullet/boolit diameter, so it must be something else. Smokeless with jacketed vs. black powder and lead and of course projectile design? Any thoughts?

[Larry Gibson]

btroj

"Oh? We need Tim's permission to have thread drift? Wow, didn't know that. Wonder how many other threads ended up with an RPM discussion despite the desires of the OP?"

It's his thread, I'm being polite. Politeness is something commented on here several times. Seems you want to alter the course of the thread.....I don't....comprende'?

I don't think I can buy into a theory that can't be easily defined and explained to me.

I have explained, demonstrated and proved it is not a "theory" over and over for several years now. I could care less whether you "buy into it" at all.....comprende'?

Larry, you say the threshold exists. Others say it is bunk. How are we to know who to believe?

Don't believe the "who", believe the facts and proof. Are you shooting 1.5 moa 10 shot groups out to 300 yards with your 10" twist '06 at 2600+ fps with a cast bullet? If not then you have your proof.

What EXACTLY happens of we exceed the threshold? Does the bullet deform? Is it because the bullet is like a gyroscope and the nose stays in an upward tilt even as the bullet begins to follow the downward portion of its ballistic path?

Just 2 of the many times I've explained it on this forum over the last several years;

http://castboolits.gunloads.com/showthread.php?208186-RPM-Threshold-barrel-twist-velocity-chart

Post #1

http://castboolits.gunloads.com/showthread.php?123987-RPM-theshold-discussion

Post #8

You say that the threshold is determined by velocity and twist, exactly what Tim asked about. You want to separate the discussions even thought they are one and the same.

No, the stability of the bullet is determined by twist and velocity. The twist and velocity also generate RPM but that has to do with the rotational stability of the bullet not the RPM Threshold. As already mentioned, they are 2 different phenomenon. The RPM threshold is determined by the amount of imbalance in the bullet and the centrifugal force at a certain RPM. The greater the imbalance the lower that "certain RPM" will to be. Conversely, the lesser the imbalance in the bullet is the higher the RPM can be. A bullet under or over the RPM threshold still has rotational stability because that rotational stability is not affected by the RPM Threshold. Two different things....comprende'?

That is about all I'm going off track with this discussion on this thread. If you want to further address the issue or if you have specific questions (not challenges) you can PM me or we can discuss it on the other related thread you just started.

Larry Gibson

[MBTcustom]

Wow, I step away for a few hours and things start going south! Geez you guys!
Brad, quit poking the bear. I want Larry Gibsons opinion, otherwise I would not have started a thread and invited everyone's opinion. The very subject we are discussing is a bedfellow of RPM and external ballistics and Larry Gibson is untitled to his opinion and I want to know what it is.
Larry, thank you for your explanations. I remember the discussion we had on the phone (parts of it anyway. I'm afraid I was suffering information overload by the time we hung up LOL!) and I was hoping you would render what you did in post #77 to the general populace here.

Now, this is a good discussion, and I don't like thread drift when the talk is solid, and I really really frown on folks trying to pick a fight in my living room. Keep it civil fellers. If you've got a problem with someones on-topic opinion here, then take it up in PM and keep that garbage out of my thread. I asked for opinions on this subject, and I don't remember excluding anyone.

That said, I don't want my thread overwhelmed with one persons opinion or agenda either.

How about a little give and take?

[butch2570]

There was so much go info on this thread , wow.. But ever wonder how many things that B, Larry ,Gear and some others agree on? Many ,many things on many different topics.. But still there is no way everyone could have the same exact trial and error outcome on the fore mentioned topic, too many variable at play, No One should go away from this thread sour, just difference of opinions and as long as there are different people there will always be different opinions , self trial will be the deciding sum of these problems for the individual and said person's rifle /boolit/load etc.. You guys are too good, too much experience, and too much value to us younger guys here, to fall out over opinions of what has worked for yourselves. I'm nobody here, but I suffer when you guys clam up and won't share info, because of differences in opinion . Take it with a grain of salt and move on , YOU know what has and has not worked for YOU, but please don't quit sharing that with US ..

[john hayslip]

Lee Shaver, a gunsmith who shoots on our international muzzleloading team, who should know something about cast bullets stated in the last issue of Single Shot Exchange, that the most accurate bullet will be marginally unstable. Not sure that clears up anything but it is something to think about.

[MBTcustom]

The sky is blue.
No it's not, it just appears that way to your eye.
Appearance is all that really matters to anyone.
Your wrong, you can't extrapolate any scientific conclusions from bad information.
Saying the sky is blue is not "bad information". It's taking all the information as a whole.
It can't be good information if you have to ignore science to draw a conclusion.
The sky is still blue.
No it's not.
Yes, actually it is.
That's your perception and nothing more.
My perception is all that matters to me.

LOL!

Look fellers, why is it neccisary to convince someone else to agree with you? If your personal conviction about how to shoot cast lead is on such shaky ground that you feel you need everyone to agree with you in order to make it so, then perhaps you should modify your thinking so that you have a more comfortable ground to stand on?
I don't agree with Larry on everything, but I'm perfectly happy to disagree without ramming my opinion down his or anyone elses throat.
I give Larry props because he explains his position very well, and offers targets, referances, and pictures to back him up. That doesn't make him right, it just gives his point of view credibility. If you're going to convince someone who has an open mind (like me) to run a few tests and see if things line up, then that's the civilized way to do it.
Simply listening to someones opinion doesn't create a need for me to change mine. It doesn't have any effect on me whatsoever except to encourage a little broader thought. That does no harm at all.

If you go to college, or higher education of any kind, (which I know most of you have) you learn real fast to hold your views tight, but listen to others. In fact, since the person whom you disagree with is running the class you need a good grade in, you have to understand their view and be able to give it back to them the way they require it. By the time you get your diploma, you're a mental chameleon but you are also very able to argue your position with civility to anyone.
Only a knuckle dragger says "dis is da way it is, and me and my goons is gonna smash anybody dat says different".

Look, this RPM thing is a subject of a lot of contention. Why are there such hot debates over this? I'll tell you why, because nobody has all the answers yet. No one can say "look here, it's obvious!".It's not.
Larry Gibson has some of the best tools a fully fledged gun nut can possibly own, but he still has never seen what really happens to that boolit because he's never been able to watch it all the way from the case mouth to the target.
Now, each person is fully committed to their point of view, and I applaud that, but that's not what seems to be the issue here. Certain people wish they had a following of people that understand their view, or are jealous of certain others that have done all the handshaking, guiding, reinforcing, writing, and schmoozing required to build a following. All I can say is get off your butt's and start explaining yourself to lots of people and you'll get a bunch of folks that understand what you are saying and will back you up! Not only that, but I would think it would save a tremendous ammount of powder and primers on your part if you have 100 shooters reporting their findings and backing your position with every post.

Regardless, you have to understand that cast boolits is not a place to fight about your differences online. This is a place to humbly submit your position, and post your experiments. This is a place to grab the next rung on the ladder and give a helping hand to the guy two rungs down, and sometimes give a push to the guy that's two rungs up.
If any of you think that you are at the top, looking down on the rest of us trying to climb, you need to either turn around, or get off the ladder. Something else I might mention is that the castboolits ladder doesn't go to the clouds. It has a limit. You can only learn so much here, and then castboolits will fail to feed you anymore.

I would encourage everyone who is trying to learn this sport here, that if you learn nothing else here, you must learn to feed yourself, because someday, that's the only way you will advance. It's bitter when you reach the limit of what we can teach you, and you find there are no more teachers. When you realize that there are only one or two guys that are ahead of you. Sure they can give you a hand (maybe) but their viewpoint is going to be very narrow. It's one mans experience, and as such, is fallible.
I'm glad that I'm not anywhere near the top rung, because at this time I have many many teachers, but I know that will come to an end someday, so I am trying to learn how to learn for myself. After all, that's how Larry, Bob, JD, Molly, and so many others managed to get where they were. To say nothing of shooters like Fryxel, Ackley, Keith, McGivern, and others got to where they were. They were good at teaching themselves, and they were good at writing down their opinion. That's it. They put their pants on one leg at a time just like the rest of us, but they used their brains for more than to keep their ears from slapping together, and they wrote about what they did.
This is just a forum. This is lightweight training for the major leagues.

[Love Life]

The only way to glean the info is to shoot. I don't know why people are busy pushing their opinions down each other's throats. Do the tests and...PROVE IT OUT!!!

I had a theory on slow powders and barrel life. I dropped near $400 on a barrel and proved my theory was wrong by burning the barrel out.

You all have accurate rifles coming. Put the ammo together, shoot it, take notes, compare notes, report back.

It's ok to be wrong, it's ok to be right. You all have the tool (gun) coming to aid in your reseach. Now you need near perfect boolits...

[MBTcustom]

The only way to glean the info is to shoot. I don't know why people are busy pushing their opinions down each other's throats. Do the tests and...PROVE IT OUT!!!

I had a theory on slow powders and barrel life. I dropped near $400 on a barrel and proved my theory was wrong by burning the barrel out.


You know, I never really gave you props for that Love Life. That was inspirational to say the least, and that rifle taught me more than any other up to this point, so thank you for letting me build it for you! That's the way to run an experiment by gums! Put your money where your mouth is, roll the dice, and write down what happened good or bad.
Awesome.

[Love Life]

I had to know, and all I proved was each rifle is a law unto itself.

It started with me wanting to know WHY a 308 barrel is good for 5,000+ rds (maybe a little less if you fire hot and fast non stop). The answer there seemed to be pressure and the fact it is a balanced cartridge.

Then that was turned upside down by George Gardner from Gnats A** Precision (GAP) rifles when he brought out the 6.5 SAUM. It is a 6.5 caliber launched at 3100 FPS using H1000 powder. Using his load it stays in the same sedate pressure envelope of the 308 Win, but has some juice behind it. He went on to win the Sniper's Hide Cup with over 4,000 rds on that barrel.

So, an overbored cartridge with slow powders and he went to 4,000 rds. Others shooting the cartridge report much the same. The kicker is that Mr. Gardner and others didn't baby the barrel by taking an hour to shoot 5 shots. They shot how they pleased.

I got to thinking and figuring. Doing the math, using Retumbo in the .243 with the 105+ gr weight class of bullets would keep me in 308 pressures. So if 1+1=2 then I should have gotten way more than 820 rds out of that barrel before it croaked. As we all know, that was NOT the case at all...

Of course this has no bearing on twists and such, but it just goes to show that the amount of variables facing this equation is staggering.

Then you throw cast boolits into the loop which adds another entire layer of variables. Does the boolit have voids? Where? Was it well filled out? Good lube? Who knows? As we know, boolits are finicky little monsters. I'm wondering if this quest should be conducted with swage paper patched boolits, as the little variables in necked and lubed boolits may cause issues that give false positives and negatives.

[Love Life]

To address the thread question: Ideal twist rates for cast boolits vs. jacketed. Different? Why?

I believe the lowest rung ( think 55 gr FMJ fodder) swaged jacketed bullet is still head and shoulders above the best cast bullet. Lack of voids, plus you have that tough jacket to take the stank from the barrel. Just my opinion on it.

With jacketed you have wiggle room. With cast it is an all or nothing proposition.

[ol skool]

[I]...You can strive for cast bullet perfection and launch or you can slow the twist down to keep the RPM under 140,000.

Yes that requires a different barrel. But if building a cast bullet shooter why not consider the slowest twist that will properly stabilize the chosen cast bullet? Note here there is a difference between minimal stabilization and "stabilized" as far as twist rate goes. The idea that a slower twist some how limits you to just the one cast bullet and some how is not "versatile" is mistaken...Larry Gibson

Ok. Total noob here. I see ego's getting in the way of good info that I need to use for my paralysis by analysis. So I'm going to interject a stupid question. You know, kind of like when your 4 year old kid comes up and asks if you and Uncle Remus (brother) are not going to be friends anymore. (Anyone else a Zappa fan?)

So I'm pondering reboring a 308 to 338 for this boolit (http://castboolits.gunloads.com/showthread.php?133410-NOE-338320-201Gr-FN-%28SHIPPED%29) primarily but may want to use a 225gr Lee at some point in the future. Hence my interest in this thread.

What is the minimum RPM to stabilize a boolit so I can calculate a twist for the barrel that may work for the heavier Lee as well? I'm calculating max RPM by (mvfps x 60 seconds) * (12 / twist). Is there another magic formula?

Also smearing, deformation... How many gooves, eh? There's a new question, huh? I can't see it would matter as long as it's not micro-groove. But thought I'd ask...

[MBTcustom]

Ok. Total noob here. I see ego's getting in the way of good info that I need to use for my paralysis by analysis. So I'm going to interject a stupid question. You know, kind of like when your 4 year old kid comes up and asks if you and Uncle Remus (brother) are not going to be friends anymore. (Anyone else a Zappa fan?)

So I'm pondering reboring a 308 to 338 for this boolit (http://castboolits.gunloads.com/showthread.php?133410-NOE-338320-201Gr-FN-%28SHIPPED%29) primarily but may want to use a 225gr Lee at some point in the future. Hence my interest in this thread.

What is the minimum RPM to stabilize a boolit so I can calculate a twist for the barrel that may work for the heavier Lee as well? I'm calculating max RPM by (mvfps x 60 seconds) / (twist / 12). Is there another magic formula?

Also smearing, deformation... How many gooves, eh? There's a new question, huh? I can't see it would matter as long as it's not micro-groove. But thought I'd ask...

Assuming you are talking about 338 federal (I gotta get me one a them!) and you're wanting to shoot right around 2400fps, I would think a 20 twist would be the minimum you would want to go.
You could feasibly go as far as 21, but my chest aint hairy enough to recommend that. At 21 twist, if for any reason you can't get above 1800fps, you are going to be on really shaky ground.
That said, I like to hedge my bets, and if I were to do what you are contemplating, I know I would get 18 twist.
Just like with the 30 cal. btroj said 12, Larry Gibson said 16, I'm standing right in the middle at 14 and calling them both nuts! LOL!

Oh, and I would go three groove. I have no reason except I like odd numbers and it works.

[Larry Gibson]

ol skoo

A 16" twist will fully stabilize that bullet from 1500 fps up. With the 338-.308 or the 338-06 the maximum velocity obtainable will be under the RPM threshold. Thus accuracy from the 1500 fps upwards of the maximum for either cartridge should be very good with a properly designed cast bullet if you do your part. The potential limitation I see with that bullet is it is designed for hunting at somewhat lower velocities. The limiting design features appear to be; the bearing surface is at or less than 50% and the a major portion of that long nose is unsupported. Those 2 design features may lower the RPM threshold in either cartridge and accuracy may not be the best above 2100 - 2300 fps unless a very hard alloy is used. An 18 or even the 20" twist goodsteel recommends may attenuate that problem but the minimal velocity for stabilization goes up. Thus with those slower twists that bullet may be only useful at top end velocity. Whether the design features of that particular cast bullet will allow that would have to be seen. That is why I fudge to the side of the 16" twist.

Larry Gibson

[MT Gianni]

I don't think that is the cause. So far I've read it, as have others, since the first page and has been a topic of conversation off this site. Geargnasher has the just of it below...........................

Bob, overall it has had less that 1500 views. Many in Our Cast Boolits have 5-6 times the views in a similar time period.

[HollowPoint]

I started following this thread with some interest but I quit reading when folks started butting heads. It's hard to get usable new information under these circumstances.

I came back to reading this thread because I've always wondered about some of the same questions that were asked by the OP. In my minds eye I picture a potential culprit to at least a couple of the questions posed by this thread as having to do with imperfectly cast boolits that appear -superficially- perfect.

You know, those invisible voids that have already been mentioned before. It occurred to me to ask if anyone has made a lead bullet swaging die for a given 30 caliber lead bullet so that it could be formed via a swaging die rather than cast using a bullet mold? This may be a good way of eliminating the possibility of unseen voids or imperfections in our cast bullets; at least for testing purposes.

By eliminating the invisible imperfections we eliminate one of the potential factors that cause us grief regardless of velocity or twist rate. My cast bullets shoot well enough at velocities up to 1700 fps but I'll inevitably get one or two or three or four that have a mind of their own and go off as "Fliers."

I have two 30 caliber rifles. One is a 10-twist and the other is a 10.6 twist. I've shot both of them at just a tad over 2000 fps before and neither one would group worth a darn at a hundred yards. Neither did either one leave leading in the bore or oblong holes in my target.

Was this due to imperfections in my cast bullets that I didn't know about or was it due to an "RPM/Barrel Twist" thing that was eluded to by the OP? If your bullets ARE cast concentrically, loaded concentrically and flying concentrically, it's hard for me to wrap my head around "RPM" or "Barrel Twist" as being the problem.

It's right about now that a good lecture on BHN and Paper patching would come into play.

HollowPoint

[Love Life]

I too have been kicking around the idea of a set of swage dies to swage some lead rifle bullets (I think they are bullets because they are swaged). However; the issues in my mind with that are:
A) A suitable alloy. Will the swage dies be able to swage the harder alloys?
B) Lube. I reckon you could cast first of your preferred alloy in a lub grooved boolit mould, lube the groove, and then swage it to final shape. That would eliminate voids and leave some lube...I think. Would it leave enough lube though?

[geargnasher]

Swaging can help, LL, but it will by no means mitigate the need to understand how to dance the Rhumba with the big, purple elephant. You're still thinking from a jacketed bullet frame of mind, which won't get you very far with cast.

Gear

[Larry Gibson]

Swaging can help, LL, but it will by no means mitigate the need to understand how to dance the Rhumba with the big, purple elephant. You're still thinking from a jacketed bullet frame of mind, which won't get you very far with cast.

Gear

Very well put, concur 100%.

Larry Gibson

[35 shooter]

goodsteal i can't offer anything constructive on your bbl twist theories, although you have got my head spinning on it lol. I would however like to get your and Larry Gibson's opinion on the 358009 280 gr. boolit in 35 whelen in a 14 twist bbl. I may get 2 different opinions and that will be just fine, i'll figure it out through testing from there. How fast can that boolit be pushed while maintaining 1 to 1 1/2" accuracy (i know that will be just best guess) using something along the lines of h4895 to imr4350.
I already get that and better with a 200 gr. boolit at 2400 to 2500 fps, i just want to play with a heavy weight for caliber and don't want to make the wrong choice.
goodsteal i hope this thread comes back strong because you certainly had my attention on it. Didn't intend to post...just learn something new maybe, but since it drifted a bit just thought i'd ask your opinions on the above.

BTW i think most folks here WOULD love to shoot with Larry...not to prove anything,but just a chance to absorb some of that encyclopedia of cast boolit knowledge he's carrying around in his head. He sure better be glad i don't live next door lol!
Stop the jabs and let the learning curve continue.
Okay, sorry if this was a drift...looks like everything got going again while i was posting.

[Love Life]

Swaging can help, LL, but it will by no means mitigate the need to understand how to dance the Rhumba with the big, purple elephant. You're still thinking from a jacketed bullet frame of mind, which won't get you very far with cast.

Gear

Maybe, maybe not.

Perfect or near perfect boolits has been mentioned and discussed as being important to many things.

I pay good money for near perfect jacketed bullets and they do what they are told. Yes the jacket is a whole different variable...

So, swaging will give you a much better product to launch down your bore. Have any of you done it with swaged bullets (lead/alloy)? What I'm seeing is that the elimination of one of the most nagging variables very well may open the doors or part the clouds.

So yes, in that sense I am in the jacketed frame of mind. We have the ability to actually make perfect bullets (by opening the wallet of course) but everybody sticks to their preciously poured boolits into inert mould blocks, and they have no way in ensuring any consistency. Real consistency. Not just "My driving bands are well filled!!", but real, quantifiable consistency.

It's like trying to do brain surgery with a Ka-Bar.

However; I will not get hung up on that here. I will continue to listen to the mantra of "Fit, Fit, FIT!!! Boolit, Neck, Chamber, etc.!!"

I get it and I got it. I'm not retarded. I'm listening.

[Love Life]

Very well put, concur 100%.

Larry Gibson

Amazing!! Good thing I get to ignore neck tension, diameter, etc and just sit some bullets over 'splody powder and shoot sub-moa to 1,000 yards.

I apologize for the snarkyness, but brass prep and all that jazz is just as important in shooting jacketed. What I don't have to deal with in jacketed is sub par, off balance, projectiles...that may or may not act like accordions.

[Larry Gibson]

It does, sorta.

Treating a cast bullet the same way you treat a jacketed bullet at ignition is a sure way to fail. The cast bullet is fragile in comparison and needs to be treated accordingly.

Start it soft and gentle and straight and don't do anything that may let it get deformed. Throat fit is soooo critical.

Very well put, concur 100%.

cbrick

I think that was basically (very "basically" because there have been long posts, a lot of posts and some very long threads on how to do that) what geargnasher was saying. My understanding of what he was saying anyway.

Larry Gibson

[geargnasher]

Maybe, maybe not.

Perfect or near perfect boolits has been mentioned and discussed as being important to many things. It has been discussed, but most of those discussing it really don't know enough about it, but are speculating theoretically. Theoretically, we can't cast a perfect enough boolit to shoot well at HV. But I assure you many of us can and do, even those who can't shoot HV with accuracy in fast-twist barrels are casting boolits that are plenty good for the job, they just don't know how to dance with the elepant. Lots of us know how well an as-cast boolit can shoot at extremely high velocity and RPM. I do. Pdawg Shooter does. Nobade does. Bob does.

I pay good money for near perfect jacketed bullets and they do what they are told. Yes the jacket is a whole different variable...Think about how a jacket helps us dance with the elephant, and apply that to your cast boolits.

So, swaging will give you a much better product to launch down your bore.No doubt, but I can tell you that you can cast a more than adequate projectile the old-fashioned way, it isn't that difficult, and it doesn't matter as much as you think. Have any of you done it with swaged bullets (lead/alloy)? What I'm seeing is that the elimination of one of the most nagging variables very well may open the doors or part the clouds. The theory of hidden voids/weak spots/balance problems has been disprove in a different way. All your swaged boolits will prove is how good you are at dancing with the elephant, or not.

So yes, in that sense I am in the jacketed frame of mind. We have the ability to actually make perfect bullets (by opening the wallet of course) but everybody sticks to their preciously poured boolits into inert mould blocks, and they have no way in ensuring any consistency. Real consistency. Not just "My driving bands are well filled!!", but real, quantifiable consistency.A micrometer and loading scale are more than sufficient to cull boolits that aren't adequate for HV application.

It's like trying to do brain surgery with a Ka-Bar. I think a better analogy is trying to perform brain surgery with only an RN's tools and level of training.

However; I will not get hung up on that here. I will continue to listen to the mantra of "Fit, Fit, FIT!!! Boolit, Neck, Chamber, etc.!!"

I get it and I got it. I'm not retarded. I'm listening.

Achieving proper static and dynamic fit, together with load balance (pressure curve, harmonics, etc), will get you a lot further than swaging perfect boolits and using cave-man loading techniques.

Now, Rick, don't worry, I'll get to it, and hopefully so will those who know more about it than I do, but for right now, some thinkin' needs to be done here.

Gear

[geargnasher]

Amazing!! Good thing I get to ignore neck tension, diameter, etc and just sit some bullets over 'splody powder and shoot sub-moa to 1,000 yards.

I apologize for the snarkyness, but brass prep and all that jazz is just as important in shooting jacketed. What I don't have to deal with in jacketed is sub par, off balance, projectiles...that may or may not act like accordions.

The methods are not only different, but ten thousand times more important with cast than jacketed. You have to go to full-on benchrest loading tolerances and attention to vibration, pressure curve, just to equal the accuracy and velocity of factory loaded jacketed ammo with cast boolits.

Yes, Larry, you understood me correctly. The problem is, like Rick alluded to, it hasn't been explained in a straightforward, conversational way. Even then, the full understanding doesn't come until one actually ACHIEVES a good launch with components he manipulated and assembled himself, usually after a lot of false-starts and errors. I'm not saying I have a "full understanding", I don't, but I've gotten the high-velocity launch really close to right in six rifles now and a lot of the same principles apply. Bob described most of it when he posted about making a chamber cast and mimicking it closely with the entire loaded cartridge. Then there's alloy, pressure curve, and the little tricks that matter a lot, but that really IS a subject for another thread, and I think I have sidetracked the twist subject of this thread enough.

Gear

[Larry Gibson]

HollowPoint

"Was this due to imperfections in my cast bullets that I didn't know about or was it due to an "RPM/Barrel Twist" thing that was eluded to by the OP? If your bullets ARE cast concentrically, loaded concentrically and flying concentrically, it's hard for me to wrap my head around "RPM" or "Barrel Twist" as being the problem."

You may have a problem getting your head around it but that's ok. However you also realize you are seeing the end result of "something" that is causing; "I have two 30 caliber rifles. One is a 10-twist and the other is a 10.6 twist. I've shot both of them at just a tad over 2000 fps before and neither one would group worth a darn at a hundred yards. Neither did either one leave leading in the bore or oblong holes in my target." Assuming you are casting, loading and lining everything up concentrically then obviously there is another "game" afoot. The laws of physics and ballistics are there and are known. Thus as butch2570 puts it; "Anything that I can think of that rotates on a fixed center or axis that has a slight unbalance to one side is made worse by increasing the Rpms". We can cast, load and do all the concentric alignment we want but there still is the problem (unbalancing of the bullet) that the acceleration can and does do to the bullet before it clears the muzzle (launch). After that it is what the centrifugal force of the RPMs do to the bullet in flight that remains the question.

However, This thread is supposed to be about twist rate for "ideal" stabilization of the bullet. We can mitigate the adverse affects of the centrifugal force on the bullets imbalances by using a barrel twist that is just fast enough to fully stabilize the bullet. Doing that provides better accuracy, especially with cast bullets. The secondary benefit in seeking the "ideal" twist for a cast bullet is that many times we are then able to keep the RPM Threshold above or very close to the maximum obtainable velocity for a cast bullet in the cartridge used. That then negates the RPM threshold almost completely and we need not then concern ourselves with that.

However, in the case of your '06 you have the 10" twist barrel and knowing about the RPM threshold can then allow some movement of it upward if that's desirable. Using a better designed cast bullet that fits, an appropriate alloy, a slower burning powder with close to 100% load density and some other somewhat anal loading techniques you could push the RPM threshold upwards so 2200 - 2400 fps with useable accuracy is possible. It's not easy but it can be done.

Larry Gibson

[Larry Gibson]

Amazing!! Good thing I get to ignore neck tension, diameter, etc and just sit some bullets over 'splody powder and shoot sub-moa to 1,000 yards.

I apologize for the snarkyness, but brass prep and all that jazz is just as important in shooting jacketed. What I don't have to deal with in jacketed is sub par, off balance, projectiles...that may or may not act like accordions.

I think if you read a little more of the last couple posts you'll get a bit better understanding. A lot of the techniques of loading cast bullets to HV are the same as with jacketed bullets. We do have to be quite anal about some things just as geargnasher mentions. Much of the difference comes from understanding what is going to happen to accuracy (bad) with cast bullets if you don't pay attention to other details that you don't have to with jacketed bullets. That's because you pay a lot of $s these days for quality jacketed bullets where the manufacturer has paid attention to those details for you. Also you must understand the force of acceleration and what it does to a cast bullet vs a jacketed bullet. Just because we put a perfectly cast bullet into a perfectly prepped case in perfect concentricity to the bore doesn't mean we get a perfect bullet out the end of the muzzle. Jacketed bullets can be awfully forgiving in that regard but cast bullets are not, especially when we push them hard and fast.

Part of the intent of this thread is to discuss what we can do to mitigate that by using an "ideal" twist for cast bullets instead of the general "all purpose twists" most often found for use with jacketed bullets. BTW; a lot of very good cast bullet shooting can easily be and is done in the standard jacketed bullet twist barrels. When kept to reasonable velocities even cast bullets can be pretty forgiving in accuracy with minimal loading technique. Even some pretty poor cast bullets can give quite good yeomen accuracy out to 100 yards w/o much trouble in loading at all. Just depends on what you want.

Larry Gibson

[geargnasher]

However, in the case of your '06 you have the 10" twist barrel and knowing about the RPM threshold can then allow some movement of it upward if that's desirable. Using a better designed cast bullet that fits, an appropriate alloy, a slower burning powder with close to 100% load density and some other somewhat anal loading techniques you could push the RPM threshold upwards so 2200 - 2400 fps with useable accuracy is possible. It's not easy but it can be done.

Larry Gibson

Wait a minute.

When I mentioned that I got near 2400 fps out of a ten-twist, with "useable accuracy" (1.25 MOA for multiple, ten-shot groups at a hundred yards on different days is pretty usable), you demanded, rather rudely, to see it done in person. The implication was obvious, I think.

Now you're telling others how to do it. I can show how I did it, but I'd like to see you go first here. Please give some details, pics of groups and load details, including what tolerances or anything else specifically that you changed to "push up" the threshold compared to what you could do with your normal loading routine that limited-out at the top of the threshold. This is the sort of stuff a lot of people are interested in right now and following hoping to learn. Maybe you could start a new thread, titled "How to get good groups past the RPM threshold" or something.

Also, I'm getting a distinct vibe that you are starting to assimilate the term "pushing the rpm threshold up" with stretching the twist rate out and loading to higher velocity. I DON'T THINK SO. That would be called "lowering the RPM and increasing velocity to stay within the threshold". The threshold remains the same for the equivalent loading techniques the way I read your theory.

Gear

[Love Life]

Now I have a better understanding. Thank you.

[MBTcustom]

You have to go to full-on benchrest loading tolerances and attention to vibration, pressure curve, just to equal the accuracy and velocity of factory loaded jacketed ammo with cast boolits.

Why is that Ian?


Because we have a more fragile projectile we must load it in a manner that protects it.

Why is that Brad?


our cast bullet will easily flow into those spaces and that leads to unbalance even if we started with a perfect bullet

Why is that a bad thing?

If the RPM theory is totally wrong then none of those things shuold matter?
Why is it that when you perform the most basic ladder test to find the nodes, everything goes to pot rather suddenly?
I know it has nothing to do with RPM, because that cant be the right answer (Dont ask me why it can't be the right answer, it just cant OK?) but surely if the centrifugal force applied to the imperfections that you left or imparted to the boolit while loading and shooting it is not to blame, then what could possibly be the reason?

The way I look at it (and I could be totally wrong on this) is that the "RPM threshold" or whatever you want to call it is a schoolmaster. It exposes your errors and to a point, the limit of the very projectiles we are shooting.
Think of it like MPH on a stock car. Sure the driver can do a lot to work with what he's got, and eek out the most competitive edge by being darn handy with a clutch, but he's not a car builder, hes a car driver.
We wear both hats. We make the boolits and we also load and shoot them, but a janky boolit will only go so fast until its limits are breeched, just like a stock car can only go so fast till you hit top end on the MPH.
In order to win a race, you need to build the car and drive it better than anybody else, but when we are talking exclusively about RPM, it's like we are talking exclusively about MPH.
If you go to the dealership and buy ten brand new Dodge Chargers, take them home and rip out the governors. Then take them to the track and run em up till they top out, you might come to the conclusion that "A Dodge Charger can only go 120-140 MPH" just like Larry says that a cast boolit can only go 120,000-140,000 RPM typically.
Well, up walks a master mechanic and tells you your full of it! a Dodge Charger can do 200 all day long if you do X,Y,Z.
Next guy walks up and calls BS and says that he can get that thar Charger up to 230mph if you give him a week.
The thing is, there is still a limit to a certain process. Sure you can fudge it up or down, and sometimes you get lucky, but for the most part there is a number that nobody wants to tackle.

[MBTcustom]

If I could step in here for just a second?
I just read what Larry wrote in this thread along with what each of you fellers put down, as well as the links that Larry put up.
Just reading it, with no history to help me read anything else into it, I see the threshold described as the place where accuracy suddenly goes to pot. This can be found with any cast boolit load by doing a simple ladder test.
Also, I see him saying that the FPS (thus the RPM) where this phenomenon occurs is higher with a better fitting, better balanced boolit.
That's what he says.
That also appears to be what everybody is saying, and other than this strange aversion to the three letters "RPM" being used in a post, the difference comes down to loading techniques and groups, both of which are being refused on a matter of principle.

I think two things need to happen.
First, you fellers can apologize to eachother for the years of berating posts back and forth, and believe me, there's enough blame to go around on both sides.
Next, I suggest that Ian has the best idea yet. Start a thread and work together to hammer out a consensus on this issue. I guarantee you could all get where you are going ten times faster if you were working together.

[MBTcustom]

Ok, possibly true Tim but look at the closed sticky I linked to.

It says accuracy will begin to detonate between 120,000 and 140,000 rpm. A 2400 fps load in a 10 twist barrel is over 170,000 RPM.

Not an insignificant difference. If 170,000 is possible then what does the 120,000 to 140,000 threshold mean?

That is over a 20 percent difference, not insignificant at all.

That's true Brad, but I just ran into a wall with my 1909 Argentine reamed to 30-06 (that's another way to get a killer tight-necked 06 BTW) and when I dropped down to 1500 FPS I went from a shotgun blast to MOA.
Every rifle is different. This one has a rotten bore, and Ian's has a superb bore. Which will damage the boolit worse?

BTW, ironically, it was Ian that told me to try a tame charge of Unique. LOL!

[bnelson06]

+1. Way too much great info to get into a war here. I'm trying to soak this all up and not ready for the well to go dry on this subject.

[MBTcustom]

Looking at this another way it means I should be able to achieve the same RPM level in my 12 twist barrel so that gives me 2800 fps at 168,000 rpm.

2800 fps with that case and a 180 gr bullet exceeds the limits of what can be done with that case most likely. Problem solved, my twist rate is fine.

Certainly! If you use these top end dies, top end brass, and top end boolits, and feed them in an absolutely top end rifle, you should be able to get it up to 2800, but there is no way I could do that with the Argentine without a lot of fancy footwork, and I can tell you without hesitation that most milsurps would be just as difficult (not impossible, but difficult, especially for the average booliteer).
To the average booliteer, all he wants is to know how fast he can push without spending a fortune and jumping through flaming hoops of fire to get there, and in that case, the easy answer is to just go by the RPM theory and call it a day. In most cases, there is no reason why your shouldn't be able to get 120,000 RPM with standard, hulk smash, reloading techniques.

That said, I'm still waiting to see anything even close to this with any of my rifles. Certain people say it's possible, so I'm just taking their word for it.

[MBTcustom]

Of course, some of us are wanting to take it to the next level, and "push up the RPM threshold" as Larry puts it.
We have the tools, the means, and the dicipline to make it happen, and all that is required is to pick a rifle and git-er-done. However, without guidance or collaboration, that will be a rough trial and error way to reinvent the wheel.
I would like everyone on this sight to have both.
Right now they have neither.
All that is required is a hand shake, a buried hatchet, and some honest give and take between peers.

[MBTcustom]

I think I can safely say that many of us want collaboration. What we don't want is interference or naysaying.

The thread I want to see is all about the particulars of making better ammo, how to cast better bullets, how to size and lube them without damaging them, how to fit them, and the case, the chamber/throat, and how load differences change the ability to get good accuracy.

If we can stay on topic and keep the nastiness away then it can work. What we need to keep at bay is summed up in a single word- EGO.

What we need are open minds. Minds that don't predetermine things to not be possible. Minds that are willing to accept things at face value. Minds that are willing to speak of what is being done NOW, not what was done in the past.

I want a thread of doers, not thinkers. People who are actively involved in the process as it happens. People who are willing to get their hands dirty and DO the work.

I know of at least one other person who feels the same way.

Absolutely. So remember those fine words from my favorite book: A soft answer turns away wrath.
This can happen Brad. It can be under way in less than a week, but it takes a commitment on your part, on Ians part, and on Larry's part that no matter what, there will be no slandering, nor trolling till an answer has been arrived at.
I'm asking for just one thread where the three of you agree to work together towards the goal you are all going for. No matter what anybody says or writes.
I'm asking you to sail to the Newfoundland, and burn the ships till you have built something instead of tearing each other down all the time and undermining each other.
I would ask for your word on that, and I will moderate.
This is not a trick, nor a snide jab at anyone. I am asking you politely, for cooperation with a couple friends of mine.

[Love Life]

A thread that only the 3 people who own the "special" rifles can input or help collaborate? Nobody from any other shooting discipline is allowed to ask questions or possibly chime in?

[Love Life]

I do happen to have a 308 barrel...

Let me get the fat lady burnt out again and I'll get the 308 barrel screwed back on.

However; I feel we have all done a great job of self moderation here and I see no reason why that couldn't happen in another thread.

[jmort]

"All that is required is a hand shake, a buried hatchet, and some honest give and take between peers."

[MBTcustom]

I can't stop the static, but there is much you can do to squelch it by how you respond Brad. If anybody get's too far out of line, I would be right there to keep the dogs off your back, but the basic commitment between the shooters to keep it solid and not fight is an obstacle only you can control.
I'll do my part, but you guys have to do your's.
I'm sure that if you guys are making progress, the general membership will look on in anticipation. If it's a civil thread then people act civilly. If its a MMA free for all, then your gonna have a crummy thread that is short lived.

[Love Life]

So no laughing at each other and saying "Neener!! Neener!!! Neener!!!!"?

Things are only fun until they stop being fun. I'll fail with you and much will be learned. People can take the info or leave it.

I've been grasping at straws all over the forum from just about all the shooting disciplines trying to wrap my mind around this.

I still want my polygonal rifled barrel...

[MBTcustom]

You're rifle is almost complete Brad. I polished the barrel to a high shine yesterday. All the details are coming together. This baby's gonna shoot!
All that is left is pretty much stock work.

[MT Gianni]

I will view this with interest and any PM to delete off topic posts will be done,

[btroj]

I will view this with interest and any PM to delete off topic posts will be done,
Thank you.

I think that helps.

I also think an open agreement amongst the major parties needs to be in place. That can be hashed out via PM if required. I have already sent a PM to some regarding this concept.

[MBTcustom]

I will view this with interest and any PM to delete off topic posts will be done,

Thank you for your help.

Now you have two moderators who will watch your back.
What do you say Geargnasher?

[geargnasher]

You have my answer, Brad.

[MBTcustom]

Well if we aren't here to collaborate, learn from each other, and try to advance, then why are we here?
Why do each of you log on here?
What are you really looking for from cast boolits?
Why here and not some other forum?
If you're here to learn and teach then this is my olive branch. If you are here to settle a score, make money, gripe about what all is wrong, or just sit there like a bump on a log, then you might as well not have ever logged on.

[geargnasher]

It's been done here many times, at least once with some very specific instructions. The reason you don't see that is too many distractions by detractors, and lack of interest by participants. Nobody's going to go through all mess of drama that always gets thrown in their faces when it comes up. Just look what happened the last time I posted a good HV group. That sort of nonesense has to stop, then I might tell how I did it so that YOU can do it, too.

Gear

[Love Life]

I'll get it figured out. It's not rocket science to be honest. It just requires effort and dedication. I'll need something to keep me busy on the super long range 200 yard range I'll be using in Georgia.

[357maximum]

Brad



I admire your effort here but it ain't ever gonna work the way you want it to. If you make everyone sign a "I have read and understand what Tim wrote in the most excellent post #68 on this thread" you might have a fighting chance, but

Two big things are against you.

1. One of your coherts (the one that went from asking newbee questions to being THE SELF ANNOINTED EXPERT in a years time) is still grinding axes and taking jabs apparently. His last couple of posts in this very thread show that with GIN CLEAR clarity. One of his last posts on this thread would be classified as a personal attack had it been written by anyone other than him and would have come with consequences to anyone else had they posted the same. The same fella is now taking pages from his mentors handbook with cryptic answers and scapegoating I see. It is posted right above this post that HV is not rocket science, and LoveLife is 100% correct in that statement. One can not gain prestige and notariety that some apparently seek unless they make something look waaay harder than it is and making up terms for techniques that have been posted over and over in a different word/form on this forum this same fella excels in that skill/desire/ whatever you wanna call it. Going fast with cast in all but the most disagreeable guns simply ain't that tough......the answers you seek are already typed out in this thread and scattered all over this forum. It simply comes down to using the already proven methods and merely doing the work with each toy.

2. Most the guys that already can do cast at HV in most their toys they desire to so with have been kicked in the teeth so many times for trying to help others that they have simply quit trying and have basically went radio silent, have passed on, or simply went away.

You know what they say about insanity and doing the same things over and over and expecting different results right?


I wish you good luck, you'll need it.


:popcorn:

[nanuk]

I am new to casting, and I came here (as redirected from other sites) to learn about casting and shooing cast.

one thing I HAVE learned, is who offers information freely, who speaks in bafflegab, and who here has such a huge ego that they believe ONLY they have the right to the information, and to make money off of it.

The old, "I know something You don't know" schoolyard taunt is getting very old.

I once suggested everyone lay them out on the table alongside a ruler, take a pic and post it so everyone'd know.... as there are some who are Definitely OVERCOMPENSATING for their "Short" comings.

this used to annoy the heck out of me, but one day I had an epiphany

castboolits.gunloads.com is NOT a place of sharing information

now that I have come to understand that, I can go back to learning. (I just need to do better at searching)

[Larry Gibson]

Wait a minute.

When I mentioned that I got near 2400 fps out of a ten-twist, with "useable accuracy" (1.25 MOA for multiple, ten-shot groups at a hundred yards on different days is pretty usable), you demanded, rather rudely, to see it done in person. The implication was obvious, I think.

Now you're telling others how to do it. I can show how I did it, but I'd like to see you go first here. Please give some details, pics of groups and load details, including what tolerances or anything else specifically that you changed to "push up" the threshold compared to what you could do with your normal loading routine that limited-out at the top of the threshold. This is the sort of stuff a lot of people are interested in right now and following hoping to learn. Maybe you could start a new thread, titled "How to get good groups past the RPM threshold" or something.

Also, I'm getting a distinct vibe that you are starting to assimilate the term "pushing the rpm threshold up" with stretching the twist rate out and loading to higher velocity. I DON'T THINK SO. That would be called "lowering the RPM and increasing velocity to stay within the threshold". The threshold remains the same for the equivalent loading techniques the way I read your theory.

Gear

I would ask that you read the thread that btroj posted in the next post of two; http://castboolits.gunloads.com/showthread.php?208186-RPM-Threshold-barrel-twist-velocity-chart

If you'll note in there I say the threshold can be pushed up, and it can. As to the '06 with 10" twist being accurate "near 2400 fps" it was not with multiple 10 shot groups at 1.25 moa. The complete details can be found with a search. The testing was done several years ago by my self and bass ackwards and was quite well documented on this forum. All of the techniques used you describe on the other thread now running were mostly used plus a bullet of proper design for HV in the '06 case was used. In that concurrent thread I see little to no discussion of proper cast bullet design for HV, especially in faster twists to push the RPM threshold up. I would interject some helpful comments in that thread but I haven't because I suspect the response would be similar to that when I offered advise in your design for the 30x57 thread. Yourself and 2 - 3 others would simply come back with the same old arguments instead of looking at it with an open mind considering what I've demonstrated at HV with cast bullets in 10 and 12" twists also. Thus I simply choose not to comment as I am very tired of it all. That is why, in this thread, I was adamant with btroj not to go into a discussion of the RPM threshold.

I didn't "demand to see it done in person" rudely or not. To "demand" requires authority and I have no authority to make you do anything. I asked, numerous times, for you simply to show me how you do it.....not that it could be done but rather how you do it. You refused even though I was at Kerrville. It is your refusal to show me how you do it that lends credence of many to doubt you can. I do not doubt it can be done as I have done it. It is the "how" I wanted to see because I like to learn and expand my knowledge to better understand cast bullet ballistics. I have the impression I could learn from you the same as you could learn from me but that needs to be a two way street.

Also you are misinterpreting your "distinct vibe". I often describe how to push the RPM threshold up when they have faster twists in their rifles and offer that advise to many here. However, the topic of this thread is the "ideal" twist as goodsteel stated with the implication if building a rifle why not use the "minimal" necessary twist so as not to spin the bejesus out of the cast bullet. That is the difference; if you already have a rifle with a given barrel twist then you must deal with that. If you are building a rifle then you don't have to "deal" with a given twist. You can have a twist that is best suited or "ideal" for the bullet(s) you intend to use. Thus I am not assimilating one term into the other as they are two separate and distinct situations.

BTW; "lowering the RPM and increasing velocity to stay within (actually under) the threshold" is a very easy way to accomplish accuracy at HV with cast bullets if one is building the rifle. That is the real point of being able to select the "ideal" twist, eh?

Larry Gibson

[Larry Gibson]

How do we get decent 2200 to 2400 fps accuracy from a 10 twist barrel when this far ascends the 1944 fps that gives us the upper rpm limit of 140,000?

http://castboolits.gunloads.com/showthread.php?208186-RPM-Threshold-barrel-twist-velocity-chart

Are you saying that with good load technique, a good chamber and throat, and good bullets that the threshold can be beaten?

If you read my post #1 in that thread you'll find it says; "The RPM threshold is not a set “limit” of RPM or velocity.". A complete reading of that post explains that in detail. Basically there is no "upper limit" of a specific RPM. Goodsteel's synopsis in his last post of what I said in that thread is correct.

And no, I am not saying the RPM threshold "can be beaten". I am (my opinion on this is changing, read caveat below) saying it can be pushed up with "good load technique, a good chamber and throat, and good bullets" plus several other techniques. The RPM Threshold can also be easily lowered by the use "poor" of improper of any of those things or techniques.

Caveat; I am coming to find, as I measure the psi, that when the pressure gets to the point the alloy begins to plasticize (I believe geargnasher mentions this in a post) that the RPM threshold becomes apparent with lost accuracy. It appears that plasticization of the bullet has the effect of lowering the RPM Threshold regardless of the velocity/RPM. For example; with my 14" twist .308W Palma rifle 2700 fps is giving 138,850 RPM. Shooting a 311466 I can hold accuracy to 2600+ fps with AA4350 which is 105% load density. The psi runs around 41-42,000 psi +/-. Going to a faster powder such as Varget or RL15 is needed to push the velocity upwards (haven't tried LeveRevolution yet) but the psi increases above 42,000 before velocity reaches 2600 fps and accuracy is lost. Thus the concept of the slightly increased case capacity of the 30x57. That should enable enough slower burning powder such as AA4350, RL19, H4831SC or RL22 to be used to increase the velocity and keep the psi (to keep the bullets from plasticizing) under 42,000.

That's the idea anyway. I'm waiting to find a 16" twist barrel so goodsteel can barrel a rifle for me. If the 30x57 doesn't have the case capacity I will lengthen the chamber to 30-06 (another potential benefit of the 30x57 cartridge design when used in an '06 length action).

Larry Gibson

[Larry Gibson]

At least YOU know how to capitalize my nickname, thank you.

Now, you want the truth? Here it is: This will not be possible as long as Larry Gibson participates. The reason is simple, he has dug himself into a theory which originally (though it has and continues to evolve greatly over time) stated that what we are doing with HV cast is impossible, and he doesn't want us to succeed.

If you don't believe that, look at past history. Every time someone claims to have busted the RPM threshold, he goes berserk and destroys the thread through many clever techniques, the last of which is by insulting members to the point that they get themselves banned by trying to defend themselves. Those who don't want to get banned just go away. It works every time, and his theory is safe. Now, granted, he's modified his theory over the years to gradually accept that maybe, just maybe, there are ways to "push it up", so it might be possible for him to help prove that and save "face", but basically, if you learn to do what he can't yet do, you don't really need to worry about RPM at all and his theory becomes moot. That would be devastating to him, ego-wise and credibility-wise. So I ask again, do you really think he wants us to succeed? And further, do you really think he's going to give it his best effort to prove that there was a lot about HV shooting he didn't know?

Brutal honesty, and truth. There needs to be a lot more of that around here.

Gear

Well, I made my last 2 posts above with the air of getting on with a reasonable discussion of all this so we could all learn and succeed. With this post from geargnasher, who has quite clearly now stated his position, and btroj's desire to leave an important ballistic part out of the discussion (RPM) I see we still aren't going to discuss anything as their minds are certainly made up; their way or the highway.

Not much to say other than I am very tired of the continual personal attacks by these two and a couple others. So let's just make them happy. Adios to everyone here, especially the many good friends I've made. The forum is theirs.

Larry Gibson

[MBTcustom]

Well, I made my last 2 posts above with the air of getting on with a reasonable discussion of all this so we could all learn and succeed. With this post from geargnasher, who has quite clearly now stated his position, and btroj's desire to leave an important ballistic part out of the discussion (RPM) I see we still aren't going to discuss anything as their minds are certainly made up; their way or the highway.

Not much to say other than I am very tired of the continual personal attacks by these two and a couple others. So let's just make them happy. Adios to everyone here, especially the many good friends I've made. The forum is theirs.

Larry Gibson

Don't leave just yet Larry.
The olive branch has been extended, and it takes a very special type of person to slap that to the ground and spit on it. I don't think that Gear, or Brad are that low.
However, you can't just throw years of hard feelings out the window at the drop of a hat. Especially if you're from Texas. LOL!

[Love Life]

Well...this didn't turn out well.

Anywho, while everybody is busy trying to figure out who has the biggest...ummm...caliber, I have been kicking thoughts around in the ol' brain housing group.

Where I plan to start:
When I get the 308 barrel screwed back on: Get a chamber cast and chamber pound done. Why both? Why not? This will give me my optimal case OAL so I can trim just enough to where I won't pinch a case neck and there won't be a canyon between the case mouth and the goods. It'll also give me the info needed for ordering a mould.

Boolits: Once I have my measurements then I'll order a custom mould. I plan to order it big and then bug Buckshot to make me a set of push through sizers so I can size down as needed. Maybe a good size reduction will help in eliminating those unseen voids...maybe not. You never know until you try. I may even order a mould with different sized (diameter) cavities so I have a lot to play with.

Alloy: I'll order from rotometals so I have foundry certified. I'm debating between hardball and lino, but I'll probably order both.

Lube: I have speed green so that ought to do the trick. Love me some Speed Green.

I want to test a bunch of things here. Bullets sized to bore, .001 over, .002 over, etc.

I've got to measure 308 blank neck thickness as that may allow me somewhere to play if the neck of the 308 tube is huge.

Powders: I have a bunch, and I'll play with them all.

This rifle barrel was an easy sub MOA performer and is chrome lined. Should be fun.

Ya'll keep fighting (even though I wish you wouldn't) and I'll keep on pushing.

[geargnasher]

Well, I made my last 2 posts above with the air of getting on with a reasonable discussion of all this so we could all learn and succeed. With this post from geargnasher, who has quite clearly now stated his position, and btroj's desire to leave an important ballistic part out of the discussion (RPM) I see we still aren't going to discuss anything as their minds are certainly made up; their way or the highway.

Not much to say other than I am very tired of the continual personal attacks by these two and a couple others. So let's just make them happy. Adios to everyone here, especially the many good friends I've made. The forum is theirs.

Larry Gibson

I did not state my position there. Only Brad and Tim know what it is exactly, as I have responded to PMs fro them. You do not know what it is, and cannot imply from my post what it is. I can tell you that what you assume about me is wrong, though.

That was not a personal attack, it is a viewpoint of a situation, backed up by some ten years worth of recorded history on the subject and a great deal of study about how to make something productive out of discussions that DO get personal, and DO turn into actual verbal fights. Anyone who cares to look into that can draw the same conclusion I have, and who it is who starts the attacks in the first place. I mean attacks, not valid and well-intentioned questions or devil's advocate scenarios.

Gear

[Mooseman]

You cannot solve basic engineering / ballistics/ aerodynamics/ accuracy issues without taking ALL the variables into account.
Long range shooters know that wind, humidity, temperature also play into accuracy as well as bullet design, powder used etc. The list goes on and on. Some of us have discovered other factors not expressed here... Like Bullet bases affecting accuracy.
Agreeing to disagree and remaining civil while collaborating Data is what any true Team of engineers/scientists will do to achieve the goal set forth , anything else is a just banter back and forth with ego and drama in the mix...
The first thing I was taught was the ABC's. A affects B which affects C !
Talk is cheap , the proof is in the X ring blown out of the target at extreme yardages...
Rich

[MBTcustom]

You cannot solve basic engineering / ballistics/ aerodynamics/ accuracy issues without taking ALL the variables into account.
Long range shooters know that wind, humidity, temperature also play into accuracy as well as bullet design, powder used etc. The list goes on and on. Some of us have discovered other factors not expressed here... Like Bullet bases affecting accuracy.
Agreeing to disagree and remaining civil while collaborating Data is what any true Team of engineers/scientists will do to achieve the goal set forth , anything else is a just banter back and forth with ego and drama in the mix...
The first thing I was taught was the ABC's. A affects B which affects C !
Talk is cheap , the proof is in the X ring blown out of the target at extreme yardages...
Rich

I couldn't agree more. The whole point of a collaborating thread is to reach a mutual understanding. Asking one participant to change the basic way they view this sport, is not just childish, unreasonable and selfish, it's downright unfair.
Larry does not understand the opposing position (frankly, neither do I) but it's equally obvious that Ian and Brad do not understand Larry's position either (which I feel I have a better grasp of right at the moment because it is explained more clearly.)

Fighting over it has not rendered a positive outcome for the last ten years, (no big surprise there) so why not do like everyone else throughout history who wanted to advance their knowledge, and WORK TOGETHER?

[Love Life]

Kestrel 4000 and wind flags...Mmmmm good.

Boolit bases or bullet bases? Which are you talking about? FB VS BT VS RBT?

Don't forget Altitude and DA.

[Mooseman]

Cast Boolit bases, j word bases, etc. there is more to it as many documented experiment from the 1800's forward have proven if one would read what has been done by people like Whitworth , and Mann , and others.

[Love Life]

Indeed.

[RoyEllis]

..... gripe about what all is wrong, or just sit there like a bump on a log, then you might as well not have ever logged on.

Hope it don't make anyone mad, but I'm here to gripe about what is wrong, (without taggin & baggin boolits with paper I can't get GOOD accuracy past approx 2150-2200fps with cast) and I'm firmly planted on my log, even if I do look like a bump on it cause I want to be close enough to the fire to hear what everyone has to say.
Since I can't figure out what I'm doing wrong (or not doing right) to hit accurate HV cast loadings, all I got is ???s to offer...so I figger to shut up, sit back & soak up all the knowledge I can.
So there Tim....neener, neener, I ain't giving up my log!:bigsmyl2:

[MBTcustom]

True, except you forget one significant item.

I am speaking of ONE specific gun in my case. The barrel twist is what it is. That isn't changing, ever. I also have a set velocity goal for it.

Those are no longer variables, they are set in stone.

What I want to discuss is how to get to my goal with a cast bullet and good accuracy.

I am not interested in discussing what my goal should be, I have set it.

People can either help me reach my goal r decide that it is a fools errand and bow out. I have stopped caring what others think.

So, do people want to help ME and MY gun reach a specific goal or would they rather tell me what gun I should be using and what my goal should be?

It really is that simple. The gun is what it is. Period. Can't be changed. Twist rate was set long ago by Kreiger. My velocity goal is what I want to ACHEIVE. How we get there is the ONLY thing I am interested in discussing.

Brad, why do you continually look at the RPM threshold as a limit, or a way to say this far and no further?
I don't see it that way. I see the threshold as a schoolmaster that will teach you how to push further. You start with your best guess for a load and start working up. At a certain point you hit a wall (the RPM threshold) at that point, I'm not saying you throw in the towel and give up. What I'm saying is that you recognize what is happening and set up shop right there changing one thing at a time till you see what tightens the group up. Then you push further till you get stopped again. You know its imperfections that are jerking the rug out from under you somewhere, so you can progress.
To say that the RPM theory is bunk is to blow right past that stopping point, or start well past the RPM threshold and start playing cleanup. Seems that is a very haphazard way to cast about (pun intended) for answers. Nobody is asking you to change your twist rate (Personally I think you picked the perfect one to learn from) and no one is asking you to give up on anything. All I'm saying is that the RPM theory is not the only way, but it's a way of thinking about this in a straightforward scientific manner, that definitely works for some people. I'm not asking you to buy it hook line and sinker, just quit laying your hand over the mouths of people who think that way. It costs you absolutely nothing to hear another point of view and while you may disagree with Larry on this issue, you would be an absolute fool to throw everything he says in the trashcan, just as he would be a fool to ignore anything you have observed, measured and tested.
Why does the RPM threshold and the discussion of it threaten your personal constitution so much? It's just a way of looking at things just like algebra, calculus, or trig. Nobodies trying to make you change your mind on anything. All I'm asking is that you find a way to share information in a professional manner and quit lambasting Larry every time he thinks about breathing the words "RPM threshold".

I went 20 rounds with a guy at work who was a flaming liberal. I detest everything he stands for, and the basis of his every thought. I argued with him respectfully as a peer. Went round and round with him, and I learned quite a bit about the liberal agenda and several times he gave me pause for thought, and I had to reassess my values (which is why I kept going round and round with him). It was obvious that I was talking to the very guy that was going to cancel out my vote at the poles, but I kept my cool and discussed things. I never felt a compulsion to knock him out, or jerk his underwear over his head (OK, I lied) but I worked with him effectively for months. We built some cool stuff together. Does that make me less of a man? Did I feel the need to vote for Obama? NO. I could carry on an adult conversation without ramming my opinion down his throat.
That's all I was asking of you and Ian, and I didn't think that was an unreasonable request.
In this thread, Larry has been nothing but civil and helpful, unless he was answering a direct, unwarranted attack on his character. Who could blame him?

[357maximum]

Tim

I wish I could express my thoughts in the way that you can. Good on you and thank you.

signed,
Sometimes one of the guilty parties whose opinions are strong and that lacks the skills to properly express himself via the written word.

[MBTcustom]

Well then! I'm just going to get off here, and go get to work on your rifle.

[357maximum]

Castboolits may have just set a new record. A thread that basically got deleted from frustration before it ever even existed......all you can say at that point is WOW, just plain WOW.

[Mooseman]

It has NOTHING to do with what I think of the threshold. Get past that.

It has EVERYTHING to do with making MY rifle shoot to the best of my ability. I don't care about twist of anything else. The gun is what it is. Period.

Why does this keep coming back to a theory?

My gun is NOT a theory, it is what it is.

I want to make it shoot well at high velocity, nothing more. My rifle does give a damn about theory.

Why is it so hard to understand that I am talking about ONE specific rifle and getting the most of it. I don't want to talk theory or what my rifle should have been.

One gun, one goal. Period.

Why is my asking for a discussion on making my rifle shoot to its best being confused with a discussion of a theory that has been rehashed so much?

The gun is what it is! The goal is what I made it! That is written in stone. Why discuss rpm theory to when the target velocity and the twist that Kreiger cut determine the rpm?

Why does this keep going back to rpm theory discussion? I have made it painfully clear I'm not interested in that at all. I want to talk about making my gun shoot better.

Dang Tim, it is so simple.

When did this thread become about YOU and your gun ? We can have the exact same gun and yours will shoot different than mine...
If I said I dont care about your gun , it means I dont care about anyone elses gun or whether they learn or not...I am at a loss for words as to your attitude here.
Those who fail to learn from others who have worked on these problems are doomed to make the same mistakes .

[TXGunNut]

Then start attacking the variables. -Love Life

Therein lies the difficulty. When we learned to reload someone most likely told us that each rifle had a personality and was a law unto itself. That bit of wisdom isn't exactly true but it helped explain the nearly infinite number of variables involved in getting a rifle to shoot really well. Then we learned to cast and a our rifles developed a whole new "personality" with the new set of variables encountered when casting.
We're dealing with physics here, not personalities. This could work but my head hurts after the first page. I'll have to check back later. Let me know what I can do to help.

[Love Life]

For the love of dinosaurs!! STOP!! JUST STOP ALREADY!!!!

Lets discuss shooting. Nothing else.

[Mooseman]

I was never referencing THIS thread, I was speaking of the thread I desired.

Had you been included in the numerous PMs you might have known that.

This is a discussion that has spanned a few threads.

But YOU are Talking in THIS Thread !!!
Ray Charles could see that....

[btroj]

Cleaned up THIS thread for ya