High velocity loss of accuracy

[haynk]

A long time ago I read that cast bullets started to melt at high velocity, becoming out of shape and balance, therefore becoming unstable and losing accuracy. I found accuracy to go away above about 2000 fps in my 30-06, using Lyman 311299 200 grain bullet. It has been recommended to me that accuracy is better around 1500 fps or less. Side note: The old Winchester 50-100-110(think I have that right) was mentioned in a novel so I looked it up in Cartridges Of The World, which listed a high velocity load offered by Winchester around 1900, using lead bullets, at 2250 fps. Can anyone shed any light on this?

haynk

[35 shooter]

You can use the search feature here and punch in "30 xcb" and get a ton of info on some of the things it takes to shoot faster with cast boolits.

Twist rate versus length and weight of the boolit, boolit fit in the throat, using slower powders to fill the case for a gentler send off of the boolit by reducing pressure, also what alloy and the hardness or bnh of the boolit can all affect how fast you can go. Lots of variables.

Btw, if your 06 is a 10 twist your doing very good to get good accuracy @ 2000 fps.
You may have to change a few things to get much faster.

[Larry Gibson]

For a quick understanding of exactly what causes the "High velocity loss of accuracy". read this sticky;

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

The "The RPM Threshold; Tale of Two Twists" sticky thread can give you an idea of how we discovered the answer to your question and the path we started down.

http://castboolits.gunloads.com/showthread.php?245302-RPM-Threshold-A-Tale-of-Three-Twists-Chapter-II

As mentioned by 35 shooter the 30 XCB threads will give you an idea of what can be done and how far we've gone. We didn't find any melting of the bullet, contrary to myth, until we pushed over 2950 - 3000 fps.

Larry Gibson

[w30wcf]

..........Side note: The old Winchester 50-100-110(think I have that right) was mentioned in a novel so I looked it up in Cartridges Of The World, which listed a high velocity load offered by Winchester around 1900, using lead bullets, at 2250 fps. Can anyone shed any light on this?
haynk

haynk,
The factory 50-110 W.H.V. (Winchester High Velocity) loading (2,200 f.p.s.) was with jacketed bullets. The lead bullets were used only with black powder in factory loads.

In addition to Larry Gibson's excellent information, if your rifle has a 4 groove barrel and or the long bore riding portion of the bullet does not fit the bore, loss of accuracy will be the result as velocity increases. I have a Rem 788 30-30 that will push that bullet to almost 2,200 f.p.s. with excellent accuracy. It fits the 6 groove barrel very well. Bullet hardness is 20 BHN.

w30wcf

[haynk]

Thanks for help. The bullet melting at high speed came from an early gun writer, can't remember which one but he was possibly writing pre WW II. It was also mentioned that as the bullet melted it left a blue streak of smoke, possibly the source of the old saying"going like a blue streak."

Re Win. 50-110: As I said, I only mention it because I saw it in a novel by a writer who researches period guns thoroughly and I looked it up in the 13th edition of Cartridges of the World and was struck by the listing of a 300 grain lead bullet Win. factory load at 2225 fps, also the same listing in the 11th ed. The high velocity load came out sometime after 1910 and is mentioned as definitely being in the 1916 Winchester catalog, so it makes sense for them to be jacketed loads, since by that time other high velocity cartridges had jacketed bullets. The first US military cartridge to be issued with jacketed bullets AFIK was the 30-40 Krag. The 6mm Lee Navy came out a few years later.

Back to main subject: At the time I was loading for higher velocity with the lead boolets, I did not have a chronograph and used loading manual figures to tell approximate velocity. The top jacketed 200 grain loads show 2600 fps, and I was well under that load level, but probably about 2200 fps. Will experiment more. Thanks again.

haynk

[runfiverun]

that long bore riding nose won't get you much over 1900 fps.
you need a proper shape to get everything into the barrel smoothly before jamming 50-k behind it and moving it along to speed.


loading manuals do not have much bearing in the fast boolit world.
I use 4831-sc in my 308 with a 165 gr boolit, there ain't no load data for that. [that I know of]
nor for the boolit I use, it isn't a production mold.

[MBTcustom]

In my opinion, bullets do melt from friction, but it doesn't happen until you start getting up into the 3000FPS range. All sorts of strange things start happening when you start getting really high velocity with cast bullets. I examined gas checks that came off in flight at 2700 FPS that showed lead soldered to the inner rim. Larry Gibson mentioned recovering 3000FPS gas checks that showed the entire base soldered over. However, very few actually shoot at these velocities, and I dare say, I do not think it is possible to achieve any sort of consistent accuracy at these speeds with a standard 1-10 twist 30-06.
I think you would have better luck with a 308 if you could get one in a 1-12 twist barrel. Then 2300FPS would be doable if you use a proper bullet design and lube.

BTW, here's an interesting article on bullet heat that pretty much sums up what I have seen from my gas checks melting off. Looks like M80 ball ammo. Bullet melting is a feeble attempt at explaining cast bullet failure by someone who does not understand what is truly going on. (it's the torque induced on the bullet by the fast rifling twist). You'll notice in the following link, that the base of the projectile is the only part that is even close to the melting temperature of lead.
http://www.advancedimagingpro.com/print/Advanced-Imaging-Magazine/Infrared-Camera-Measures-Bullet-Heating/1$180

[runfiverun]

you can do 2400 fps in a 30-30 with a 1-12 and an off the shelf mold.
it would be more, but the case volume/pressure pretty much puts the stop to that.

[gwpercle]

In the 30-06 i've had my best accuracy with a 170 grain gas check boolit Lyman 311291, over 13.0 grains of Red Dot for 1600 fps. The 1600 fps seems to be the "magic" sweet spot in my 03-A3 Springfield. Try your boolit at 1500 to 1600 and see how it likes it .
Gary

[JeffG]

You seniors, really good stuff, nice summations.

[runfiverun]

Jeff:
there is a LOT more to it than that.
Tim, Larry, and myself are holding back a lot of information, and not trying to go too deep into things.
it's all been hashed over too many times and there is more than one way to get your boolits into the top speed zones.
you have to take a lot of information into consideration and usually the rifle itself will let you down before you get what you want.

[vzerone]

In my opinion, bullets do melt from friction, but it doesn't happen until you start getting up into the 3000FPS range. All sorts of strange things start happening when you start getting really high velocity with cast bullets. I examined gas checks that came off in flight at 2700 FPS that showed lead soldered to the inner rim. Larry Gibson mentioned recovering 3000FPS gas checks that showed the entire base soldered over. However, very few actually shoot at these velocities, and I dare say, I do not think it is possible to achieve any sort of consistent accuracy at these speeds with a standard 1-10 twist 30-06.
I think you would have better luck with a 308 if you could get one in a 1-12 twist barrel. Then 2300FPS would be doable if you use a proper bullet design and lube.

BTW, here's an interesting article on bullet heat that pretty much sums up what I have seen from my gas checks melting off. Looks like M80 ball ammo. Bullet melting is a feeble attempt at explaining cast bullet failure by someone who does not understand what is truly going on. (it's the torque induced on the bullet by the fast rifling twist). You'll notice in the following link, that the base of the projectile is the only part that is even close to the melting temperature of lead.
http://www.advancedimagingpro.com/print/Advanced-Imaging-Magazine/Infrared-Camera-Measures-Bullet-Heating/1$180

I wouldn't be so quick to judge the base is melting is close to the melting temperature as they said in the article:
The glowing areas on the tail of the bullet appear to result from two effects. The bright spot on the tail along the bullet's centerline is caused by reflections of the muzzle flash off the bullet's tail, and perhaps also from the flash heating of the tail caused by the powder charge.

There are two crucial words in that statement, "appear" and "perhaps". Those are not absolutes which means they don't really know. They also said it was a reflection from the muzzle flash.

Now there is no doubt that fired bullets get plenty hot. Frictional heat is something that is real and to be reckoned with. Friction converts Kinetic energy into Thermo energy can be quite high, even to the point of welding the materials together. There is a lot of Kinetic energy in that bullet so no doubt a lot of Thermo energy is produced.

I would think that if a cast bullet gets hot enough to melt the alloy underneath the gas check that the whole area at the base of the bullet would be in a very plastic state and upon exit from the muzzle, which there is still much gas pressure pushing on the base, that it would flatten or otherwise visibly distort the base and gas check, but I have never seen any evidence of that. Most of what they said there are not absolutes.

I would especially like to hear what runfiverun has to say about that and also you.

[Larry Gibson]

At the initial stages (2950 fps +/- when the ambient temp was 90 - 100+ degrees) where my 30 XCBs began to lose GCs immediately on exit from the muzzle there was no indication of plastization or other distortion of the bullet based on the appearance of the bullet holes in the 100 yard target. Those holes were the same in appearance as those that had not lost GCs. What appears to be happening is the friction heat is great enough from the GC on the barrel that it melts the alloy in contact with the GC. The frictional coefficient of copper is higher than lead, antimony or tin so the GC, given the same induced friction, gets much hotter. We see the alloy soldered to the inside of the recovered GCs (from the inside of the Oehler Sky-Screen) it the photos. If the alloy did not melt then how was it soldered to the inside of the GC?. Thus we can conclude based on the still relative accuracy of the bullet (it hit the target and left a normal round hole) that the alloy melted only where in contact with the GC.

However, when the range of velocity was pushed to 3050 - 3100+ fps not only were the GCs being shed immediately on muzzle exit but the bullets hole that hit the target exhibited bullet deformation. Many bullets did not hit the target (more than 24" square). That indicates to me a larger portion of the bullet had become plasticized and deformed.

Certainly we are making assumptions based on secondary observation as they did in the link goodsteel provided. Making those observations is common in most every thing we do. for example we do not actually measure the psi a cartridge generates. We observe the effect that psi has on something else such as a copper crushed pellet or the strain put on a transducer or gauge. Recently Hornady introduced it's ELD-X tipped bullets. The observed with Doppler radar the erratic BCs of regular plastic tipped bullets at longer ranges. They could not actually "see" the erattic BC changes. They were also aware of the erratic changes because of erratic external ballistics by measured accuracy and trajectories....which are also secondary observation methods. They deduced the tips were melting at high velocity and thus caused the erratic performance. By changing the material so the tip did not melt the erratic performance stopped. The resulting difference is also secondary observation as they could not "see" the bullet in flight but measured the increased performance with Doppler radar, improved accuracy and flatter measured trajectories.....all secondary observations.

What I'm pointing out is we don't have to "see" everything to know what is happening. If we assume something is happening based on secondary effect/observation and we change something which solves the problem then our assumption or guess base on the observation was correct.

Larry Gibson

156071156072

[runfiverun]

stop using a low melt point eutectic alloy.

[vzerone]

Larry when you said the higher velocity did show bullet deformation on the target I believe you are correct, also on them getting to the plastic stage. I'll say that you reached the pressure/velocity limit for that alloy. Pressure can also put a bullet in the plastic state, but I tend to think it's a combination of heat and pressure. We could say too that pressure is heat.

Larry I'm editing this post because I didn't answer your question,and I apologize, how the alloy (or some part of it) was on the inside of the gas check. I believe it to be explosion welding which falls under the category of friction welding. Friction welding isn't exactly melting the two metals together, but along the lines of forging.

[vzerone]

I agree with you on that runfiverun.

[JeffG]

Definitely understood sir. Poor choice of word when I said summation. I have particularly enjoyed the high velocity with cast threads and have been trying to keep notes for future reference. I'm slowly learning.


Jeff:
there is a LOT more to it than that.
Tim, Larry, and myself are holding back a lot of information, and not trying to go too deep into things.
it's all been hashed over too many times and there is more than one way to get your boolits into the top speed zones.
you have to take a lot of information into consideration and usually the rifle itself will let you down before you get what you want.

[Larry Gibson]

stop using a low melt point eutectic alloy.

Yup, sure could do that as Speer, Sierra, Hornady, Nosler, Berger, etc. make a lot of them with a much higher "eutectic" alloy.......

However, I was under the impression this was a cast bullet forum(?) where the very largest percentage of folks use a "eutectic" alloy........correct?

The purpose of my testing was to see how fast we could really push a ternary alloy (lead, antimony and tin) cast bullet before failure. I did, in fact, test with an alloy having copper also. The problem was the more copper you added the less consistent the bullets were in size due to increased shrinkage in the mould. If there was any benefit in accuracy or increased velocity by reducing the "eutectic" properties it was more than offset by the reduction in accuracy due to the inferior consistency of the bullets. Thus while I appreciate the thoughts from some that I should continue testing with whatever they think should be done. I set a goal and I reached that goal quite satisfactorily as I originally expected to top out using the 16" twist barrel at 2800 - 2900+ fps which is exactly what and where happened with the ternary alloy.

Larry Gibson

[Larry Gibson]

Larry when you said the higher velocity did show bullet deformation on the target I believe you are correct, also on them getting to the plastic stage. I'll say that you reached the pressure/velocity limit for that alloy. Pressure can also put a bullet in the plastic state, but I tend to think it's a combination of heat and pressure. We could say too that pressure is heat.

Larry I'm editing this post because I didn't answer your question,and I apologize, how the alloy (or some part of it) was on the inside of the gas check. I believe it to be explosion welding which falls under the category of friction welding. Friction welding isn't exactly melting the two metals together, but along the lines of forging.

It may be but the fact is that no matter what we call it the end result is the same. That result is not hypothetical or semantic in nature but factual with very repeatable results. We may discuss various ideas on what it is but it is a fact. I'm not really sure we're going to get around it with ternary alloys and as I've mentioned in another post adding copper does not appear to be a solution at the higher velocity levels I using.

Larry Gibson

[vzerone]

Larry I want to speak for runfiverun as I think this is what he meant with what he said with that eutectic alloy statement, and runfiverun you step in and correct me to if I'm speaking wrong. First let's look at what eutectic alloy is for those that don't know: The proportion of constituents in an alloy or other mixture that yields the lowest possible complete melting point. In all other proportions, the mixture will not have a uniform melting point; some of the mixture will remain solid and some liquid. At the eutectic, the solidus and liquidus temperatures are the same. That's just one of many ways of saying that. Now what I think runfiverun was saying or talking about in the tin. You love adding tin and it's the tin that has the lower melting point. I think that is what you are seeing inside the gas check.

You mentioned when you went to the higher yet velocity in that test shooting that the bullet were showing they were damaged by what the target was telling you. I assume you meant something other then the groups. Could you please expand on that please?

[Rattlesnake Charlie]

You both provide a lot of useful information that I follow.

Don't let this get to where one or both of you are censored/banned.

You have both skinned cats indifferent ways.

This thread is useful to us newbeys.

I await yet more valuable information on cast boolits.

[MBTcustom]

You both provide a lot of useful information that I follow.

Don't let this get to where one or both of you are censored/banned.

You have both skinned cats indifferent ways.

This thread is useful to us newbeys.

I await yet more valuable information on cast boolits.

I don't know why I would get banned for simply reporting what I saw and the conclusion I drew from the same. Strange comment.

[Larry Gibson]

vzerone

I want to speak for runfiverun as I think this is what he meant with what he said with that eutectic alloy statement, and runfiverun you step in and correct me to if I'm speaking wrong. First let's look at what eutectic alloy is for those that don't know: The proportion of constituents in an alloy or other mixture that yields the lowest possible complete melting point. In all other proportions, the mixture will not have a uniform melting point; some of the mixture will remain solid and some liquid. At the eutectic, the solidus and liquidus temperatures are the same. That's just one of many ways of saying that. Now what I think runfiverun was saying or talking about in the tin. You love adding tin and it's the tin that has the lower melting point. I think that is what you are seeing inside the gas check.

Here's the problem; some of you are misunderstanding the intent of my several years of testing numerous cast bullet designs of .30 caliber in various twists. The entire point was to see how fast we could push a ternary cast bullet. That ternary alloy being of the common lead, antimony and tin ally that 99.9% of cast bullet shooters have been using for well over 100 years. I don't "love" adding tin, I add tin to improve the metallurgy and casting qualities of the ternary alloyed bullets only to the point the alloy is balanced in antimony and tin as to remain is solution in the lead. My tests have included Lyman's #2 alloy. Lyman's #1 alloy, linotype and COWW + 2% tin alloy. All of those alloys contain tin because it is an essential part of a quality ternary alloy commonly used by most bullet caster.

I am well aware of the eutectic properties of those alloys. To use another metal other than tin as runfiverun suggested would defeat the purpose of the testing. If he or anyone else wants to use another alloy w/o tin they certainly are welcome to. I would certainly be happy to assist where I could. But again, using other than a lead, antimony, tin alloy was not my intent. I have apply demonstrated where things fail and actually how high a velocity we can push a ternay cast bullet to and maintain linear group expansion accuracy.

You mentioned when you went to the higher yet velocity in that test shooting that the bullet were showing they were damaged by what the target was telling you. I assume you meant something other then the groups. Could you please expand on that please?

The non-linear dispersion of those shots told me the bullets were unbalanced and exceeding the RPM Threshold. Additionally the holes appeared odd shaped and larger in diameter (oval shaped also) in some instances. I've seen a lot of evidence in bullet holes of yawing and bullet tipping from poor stability and these were new to me.

My additional testing will be to fall back to the originally predicted velocity range of 2800 - 2900+ fps and see what can be done to consistently improve accuracy at 300 yards with test groups of 10 and/or 20 rounds. Sometimes we lose sight of what we have really accomplished here. Consider a 30-06 with a 165 gr jacketed bullets; we normally push those along at 2800 - 2900 fps. I am doing the same with the 30x60 XCB using a 160 - 165 gr cast bullet. Right now I am getting less than 2 moa accuracy at 300 yards with 10 shot groups. That's not quite as good as I get with my 30-06 using 165 jacketed SPs. My goal with the XCB is to equal the jacketed bullet accuracy. I have already equaled the velocity and am not really that far from equaling the accuracy.

Larry Gibson

[popper]

Serious evaluation of the IR bullet pic. Nose is hot due to attach point of shock wave - note the nose cone is NOT hot. BT base cone is not quite so hot. IMHO, the stripes between the (assumed) grooves is reflection of blooming from the camera lenses (same as the base hot spot). The blooming is overload of the detector array and temp cannot be accurately measured in those areas. As you can make out the outline of the BT base AND that is the lowest radiation angle of emitted IR, something is amiss. Th BT cone should all show the same approx. temp. My guess it's friction air luminescence, not copper temp. Personally, I would disregard any temp info from the pic. Carry on with the discussion.

[Bjornb]

stop using a low melt point eutectic alloy.

In HV testing when shooting around 2000 cast bullets with powders varying from Varget on the fast side to WC860/H-1000 on the slow side, the softer alloys never performed as well as some members here claim they do. Water dropped Lyman #2 did Ok for me to about 2600FPS, and Linotype was the only alloy that never appeared to "melt" or plasticize in any way in my rifle. I reached a max MV of 3316FPS using Goodsteel's breech seater in a 1:14 twist barrel (165 gr. bullet), still shooting within a group and with no gas check or yawing issues.

I have tried the 50/50 alloys (WW/pure), but there seems to be a speed barrier above which these bullets won't perform for me.

[runfiverun]

Vzerone you got it.
Bjorn what he wrote is what I am talking about, if you look at those higher Tin alloys you'll quite often see puddles of tin on the surface of the boolit itself.
the low melt point of that on the surface, or the alloy that melts at 450-f, would for sure be suspect to me if I was seeing melted stuff anywhere.
friction could be the culprit, gas pressure for sure don't help, and pressure inside the bullet itself wil break down the antimony crystals if there is an excess of them.

jacketed bullets do not use eutectic alloys nor alloys with tin in them at all, they are pure lead or antimonial lead.
swaging and casting are two completely different worlds.
tin is the bad guy in the swaging world it induces too much internal stress on the dies. [and will crack them]
swaging produces soft bullets with alloys such as 5% antimonial alloy [like hornady/speer uses in their HBWC bullets]
the alloy seems soft because the antimony crystals break down under pressure and allow the lead to flow over itself easier.

you need to match the alloy and boolit design to work together the XCB design does not work with soft alloys because it relies on mechanical fitment too much.
remember I have the mold too, as well as a couple of others the mechanical fitment designs always rely on hardness of the alloy to work.

[vzerone]

Larry I was amazed that bases that damaged that any of the bullets even hit the target, aren't you? By any chance did you recover any such bullets and actually see the damaged bases?

I follow along the lines of 1/2 percent of tin to antimony myself.

[vzerone]

Vzerone you got it.
Bjorn what he wrote is what I am talking about, if you look at those higher Tin alloys you'll quite often see puddles of tin on the surface of the boolit itself.
the low melt point of that on the surface, or the alloy that melts at 450-f, would for sure be suspect to me if I was seeing melted stuff anywhere.
friction could be the culprit, gas pressure for sure don't help, and pressure inside the bullet itself wil break down the antimony crystals if there is an excess of them.

jacketed bullets do not use eutectic alloys nor alloys with tin in them at all, they are pure lead or antimonial lead.
swaging and casting are two completely different worlds.
tin is the bad guy in the swaging world it induces too much internal stress on the dies. [and will crack them]
swaging produces soft bullets with alloys such as 5% antimonial alloy [like hornady/speer uses in their HBWC bullets]
the alloy seems soft because the antimony crystals break down under pressure and allow the lead to flow over itself easier.

you need to match the alloy and boolit design to work together the XCB design does not work with soft alloys because it relies on mechanical fitment too much.
remember I have the mold too, as well as a couple of others the mechanical fitment designs always rely on hardness of the alloy to work.

runfiverun I never see puddles of tin on my bullets and I certainly try to match my alloy to my pressure and velocity. I don't know why bjorn hasn't had success with the softer alloys and the slow powders he mentioned as there are far too many other cast bullet shooters that have had success with them. It could be in the manner he's using them....I don't know.

[Bjornb]

Well gentlemen.......the targets never lie, nor do the better chronographs. I'm still waiting for the "how to" with soft alloys, fast twists etc.
Maybe vzerone has some shooting results he'd like to share? Not being argumentative here; I have been at this for a while and I'm still learning.

[Larry Gibson]

vzerone

Larry I was amazed that bases that damaged that any of the bullets even hit the target, aren't you?

No, I am not surprised in the least. If all that was happening was the alloy melted where in contact with the GC enough that it "slipped off" the loss of accuracy should not and was not any greater than when a non crimp GC comes of the base of a bullet at HV. However, if additionally any part of the exterior of the bullet had become plasticized it would have "bulged" because of a lessoned surface tension from centrifugal force on muzzle exit. That would have affected the balance and flight of the bullet as previously stated. The evidence of non-linear group expansion, oddly shaped on target bullet holes and bullets missing the target are evidence that was occurring.

By any chance did you recover any such bullets and actually see the damaged bases?

No. The impact of a cast bullet at the retained velocity into a desert sand and rock berm at 110 yards +/- doesn't leave much to "recover". I have a box full of newsprint which I will soak with water to test bullet performance at 100, 200 and 300 yards. When that is completed I will have several recovered bullets to examine but I don't plan on shooting any that lose GCs as I'm quite satisfied with the probable cause we've deduced. As I stated earlier; the goal was to see how fast a ternary alloy cast bullet could be driven with 2 moa accuracy or less while maintaining linear dispersion at longer ranges. I have found that to be 2950 fps +/- with normally seated bullets in the cartridge case. Bjorn has achieved 3300 fps using breach seated bullets but did not test for linear dispersion at longer range. I think we've answered our question.

I follow along the lines of 1/2 percent of tin to antimony myself.

Not sure what you mean by "1/2 percent of tin to antimony"? How much antimony? I, bjorn and a couple others have tried lower content tin ternary alloys at 2500 - 3000+ fps and, quite frankly, found it to fail miserably. We found 2 1/2 - 3 1/2 % of tin to an equal amount of antimony mixed with lead to be about the minimal amounts for consistent quality cast bullets that were hardened enough (WQ or HT) to withstand the acceleration and psi to attain 2500 - 3000 fps. Actually I've found #2 alloy with a 4 - 5 % of both tin and antimony content to be the best ternary alloy used at the higher velocity we have attained. Linotype seems almost equally as good but I'm not sure yet that the higher % of antimony not in solution might not be a detriment in itself. I'm conducting further testing on that. We would certainly be interested in seeing your results at 2500 - 3000+ fps. We would also like to know how you came to the conclusion that 1/2% of tin was sufficient for casting quality bullets consistent enough for 2500 - 3000+ fps accuracy?

Larry Gibson

[runfiverun]

glad to see everybody could make the party.

[Whiterabbit]

Larry I want to speak for runfiverun as I think this is what he meant with what he said with that eutectic alloy statement, and runfiverun you step in and correct me to if I'm speaking wrong. First let's look at what eutectic alloy is for those that don't know: The proportion of constituents in an alloy or other mixture that yields the lowest possible complete melting point. In all other proportions, the mixture will not have a uniform melting point; some of the mixture will remain solid and some liquid. At the eutectic, the solidus and liquidus temperatures are the same. That's just one of many ways of saying that. Now what I think runfiverun was saying or talking about in the tin. You love adding tin and it's the tin that has the lower melting point. I think that is what you are seeing inside the gas check.

You mentioned when you went to the higher yet velocity in that test shooting that the bullet were showing they were damaged by what the target was telling you. I assume you meant something other then the groups. Could you please expand on that please?

aaaaaaaand if a lead boolit in the middle of a gun barrel were a homogeneous isotropic continuum at absolute equilibrium, this quoted statement would mean something. :)

OR -- There's a reason statics was easy, and dynamics was.... not. :) :)

[vzerone]

Well gentlemen.......the targets never lie, nor do the better chronographs. I'm still waiting for the "how to" with soft alloys, fast twists etc.
Maybe vzerone has some shooting results he'd like to share? Not being argumentative here; I have been at this for a while and I'm still learning.

That is true the targets never lie, but the targets can't tell who is a good shooter and who is not. Only other known good shooters can tell that.

I've been at this a long time too. Because I'm a new member here doesn't mean I'm not familiar with this forum and other forums and how the atmospheres are on them. I've lurked, read, learned, but never commented because of not being signed up. So I know the atmosphere here. I'll not post results or pictures or even mention small groups, one hole, etc. and get into the tangle of things I've so often seen, but I will comment technically.

[vzerone]

Not attempting to poke at anyone.
but to answer "why" my first and foremost thoughts are lack of chronograph usage, and operating on assumptions or comparing to published jacketed loads. Bjorn has the tendancy to test in the same manner as I attempt, every shot in the group is over a chronograph. Groups are shot multiple times to establish a repeatablity vs a "One time miricle". One differance in Bjorn and myself I "think" is, I always include my "Flyers" in the groups. After all a sub-moa will always produce sub-moa rifle/load EVERY time on demand not when the sun and moon align with venus on the forth soltice event of a new century..

why is the chronograph useful?
Altitude, temperture, and humity all play a role in velocity, as well as powder selection.
Higher Altitude = less air density = faster velocity
Temperture hotter = faster velocity, colder equals opposite.
Humity higher = denser air = slower velocity, lower humity = the opposite
An interesting side note is that Altitude, temperture, and humity will affect the burn rate of powder as well.

with all these variables it allows us to do apples to apples without calulating humity vs altitude vs temperture differances as some shoot in Florida some in the High Desert, some in Utah in high altitudes. Reguardless the weight of the charge 2675 fps is 2675 fps anywhere.

The only other factor that would marginally affect the Gryroscopically Enhanced Optimal Rotational Stability Equation (GEORSE) theroy is humity.

Yes most what you said it true, but nobody on this forum (including me) can shoot cast good enough to see the differences that those things you mention change the group sizes. Those are very minute changes that would take cast shooting in the category of group sizes like .100's maybe .200's. The real j-word bench rest shooters could detect the changes, but like I said nobody here is with cast.

I have just one thing to point out where your mention how altitude, temperature, and humidity affect the burn rate of powder that I'm not in total agreement with. Will a cartridge fire under water? Yes Will a cartridge fire in the vacuum of outer space? Yes Where you loaded cartridge at.... that particular humidity, that atmospheric pressure....is sealed in that cartridge case. Kind of like you experience with packaged food like potato chips. Bagged at sea level the bags puff up at higher altitudes. No matter where you go in the country will not change that power burn rate except for the temperature of the cartridge/powder. YES, it will change how the bullet flies....yes lttitude, temperature, and humidity do that. However you missed a few things like the Coroilis effect among others.

[Whiterabbit]

I'm not sure what you are trying to say anymore vzerone. I'm not here to question you, but your technical, as you say, comments are based on bullets being static, homogeneous, and always at equilibrium. This is not always the case (that's a tongue-in-cheek joke there) with the bullet in motion in the barrel. They lack relevance and do not get us casters and shooters closer to solving our own challenges. The inputs of other members here do accomplish that. Again, I'm not here to question the validity of your technical comments, but I am detecting a sensitivity to the perceived validity, when what other folks are likely more concerned with is relevance.

I suspect the original purpose of the discussion has been lost somewhat in the name of technical discussion, and to continue down this path is not going to get us back there.

This post is merely a "topic"al (another tongue-in-cheek there) suggestion.

[vzerone]

vzerone

Larry I was amazed that bases that damaged that any of the bullets even hit the target, aren't you?

No, I am not surprised in the least. If all that was happening was the alloy melted where in contact with the GC enough that it "slipped off" the loss of accuracy should not and was not any greater than when a non crimp GC comes of the base of a bullet at HV. However, if additionally any part of the exterior of the bullet had become plasticized it would have "bulged" because of a lessoned surface tension from centrifugal force on muzzle exit. That would have affected the balance and flight of the bullet as previously stated. The evidence of non-linear group expansion, oddly shaped on target bullet holes and bullets missing the target are evidence that was occurring.

By any chance did you recover any such bullets and actually see the damaged bases?

No. The impact of a cast bullet at the retained velocity into a desert sand and rock berm at 110 yards +/- doesn't leave much to "recover". I have a box full of newsprint which I will soak with water to test bullet performance at 100, 200 and 300 yards. When that is completed I will have several recovered bullets to examine but I don't plan on shooting any that lose GCs as I'm quite satisfied with the probable cause we've deduced. As I stated earlier; the goal was to see how fast a ternary alloy cast bullet could be driven with 2 moa accuracy or less while maintaining linear dispersion at longer ranges. I have found that to be 2950 fps +/- with normally seated bullets in the cartridge case. Bjorn has achieved 3300 fps using breach seated bullets but did not test for linear dispersion at longer range. I think we've answered our question.

I follow along the lines of 1/2 percent of tin to antimony myself.

Not sure what you mean by "1/2 percent of tin to antimony"? How much antimony? I, bjorn and a couple others have tried lower content tin ternary alloys at 2500 - 3000+ fps and, quite frankly, found it to fail miserably. We found 2 1/2 - 3 1/2 % of tin to an equal amount of antimony mixed with lead to be about the minimal amounts for consistent quality cast bullets that were hardened enough (WQ or HT) to withstand the acceleration and psi to attain 2500 - 3000 fps. Actually I've found #2 alloy with a 4 - 5 % of both tin and antimony content to be the best ternary alloy used at the higher velocity we have attained. Linotype seems almost equally as good but I'm not sure yet that the higher % of antimony not in solution might not be a detriment in itself. I'm conducting further testing on that. We would certainly be interested in seeing your results at 2500 - 3000+ fps. We would also like to know how you came to the conclusion that 1/2% of tin was sufficient for casting quality bullets consistent enough for 2500 - 3000+ fps accuracy?

Larry Gibson

Larry I figured you wouldn't get that 1/2 percent of tin. I'll tell you...it's 1/2 percent tin to every 2 percent antimony. You can tell most alloys don't need tin added then. Look I'm using less tin then you and I have no casting problems. My bullets fill out very well.

[Larry Gibson]

Larry I figured you wouldn't get that 1/2 percent of tin. I'll tell you...it's 1/2 percent tin to every 2 percent antimony. You can tell most alloys don't need tin added then. Look I'm using less tin then you and I have no casting problems. My bullets fill out very well.

Well then, you won't mind showing us how well your well filled out bullets of " 1/2 percent tin to every 2 percent antimony" perform at 2800 - 2900+ fps at 100 - 300 yards? You shouldn't mind giving us some information on the rifle and cartridge used also? Unless you "vette" your "technical comments" and demonstrate some personal expertise in the subject of HV cast bullet performance how are we to take your "technical comments" seriously and not consider that you are simply trolling.......especially considering the number of times we have been over the merits of your "technical comments" before?

Larry Gibson

[Bjornb]

Well then, you won't mind showing us how well your well filled out bullets of " 1/2 percent tin to every 2 percent antimony" perform at 2800 - 2900+ fps at 100 - 300 yards? You shouldn't mind giving us some information on the rifle and cartridge used also? Unless you "vette" your "technical comments" and demonstrate some personal expertise in the subject of HV cast bullet performance how are we to take your "technical comments" seriously and not consider that you are simply trolling.......especially considering the number of times we have been over the merits of your "technical comments" before?

Larry Gibson

Couldn't agree more. Time to walk the walk.

[vzerone]

Couldn't agree more. Time to walk the walk.

Yeah right...I'm not going there and ending like those that were banned or run off.

[Bjornb]

Figured you'd take the easy out. Bon voyage.

[vzerone]

Well then, you won't mind showing us how well your well filled out bullets of " 1/2 percent tin to every 2 percent antimony" perform at 2800 - 2900+ fps at 100 - 300 yards? You shouldn't mind giving us some information on the rifle and cartridge used also? Unless you "vette" your "technical comments" and demonstrate some personal expertise in the subject of HV cast bullet performance how are we to take your "technical comments" seriously and not consider that you are simply trolling.......especially considering the number of times we have been over the merits of your "technical comments" before?

Larry Gibson

Nice friendly atmosphere. Who made you King of the Hill?

[MBTcustom]

Would you guys knock it the heck off!
It's Christmas for cryin out loud!
I had a good conversation with the OP of this thread earlier today. One of my dearest friends. He and his father worked for an entire day two years ago over Christmas to set me up with NG to my bluing tanks (witch are actually burning as I type this).
The way this thread has gone has nothing to do with why he started it in the first place.
Why's it always got to devolve into a fight?

[vzerone]

Figured you'd take the easy out. Bon voyage.

From what I've seen you can't figure out anything by yourself. I think I'll hang around, I have a thick hide.

[35remington]

All too often we have guys making claims and then they state they don't have to show anything.

We want to believe you, but evidence and documentation always helps make one's point. This should not be surprising. Simply sniffing that one doesn't have to "prove anything" when trying to make a point.....doesn't prove anything. Show us the legwork and due diligence and your pronunciations get a whole lot more credible.

[vzerone]

All too often we have guys making claims and then they state they don't have to show anything.

We want to believe you, but evidence and documentation always helps make one's point. This should not be surprising. Simply sniffing that one doesn't have to "prove anything" when trying to make a point.....doesn't prove anything. Show us the legwork and due diligence and your pronunciations get a whole lot more credible.

35remington....and where did you see I made claims? Claims of shooting HV with accurazy and extremely small tiny groups? My God, I say what my tin ratio is after Larry Gibson asked what it was and now I have to post pictures of my bullets????? Come on...get off man. You want a video of how I make my coffee too?

[35remington]

Nope. Just results.

[runfiverun]

Done.