RPM Threshold barrel twist/velocity chart

[dtknowles]

Larry

You did not upset me I responded to make clearer from where I was coming. I don't expect that anyone still makes gain twist barrels. The only gun I know that used one was the 6.5 Carcano but that might be another way to push up the RPM threshold. Using more twist than required for a given bullet weight will make it harder to get the best accuracy but maybe spinning the bullet up more gradually would help too.

Tim

[dtknowles]

I feel your pain Larry..truly I do....you are not wrong on the "I told you so" bunch.

I have just seen the HURDLE cleared too many times by a few select shooters around here to call it a wall or a threshold into some other dimension. Not 3 weekends ago I watched as a fellow member blasted the hurdle with an as issued 1903 Springfield and also watched another member go smack over the hurdle with an as issued M1 Garand. The Springer load was actually outdenting military j-word tracers on mild steel at 250 yards and doing it with about MOA accuracy with the issue sights. The hurdle can be cleared sometimes by a little and sometimes by alot...all it takes is alot of work/playing/load/alloy development......I have done it too but mine was based more on others hard work/ sheer luck/pattern recognition than it was on hard diligent work on my part.

It would be nice to know what the load the Springfield shooter was using, you said fellow member, do you mean a member here, couldn't we get him to share his work. I have a Ruger M77 in 30-06 that is definitely not shooting MOA.

Tim

[357maximum]

Tim

It was Dutch4122 that put that sweet shooting combo together.....he does not post here much....too busy doing things to talk about things I guess. I just let him know about this thread and he will be along with the particulars when he gets a ROUNDTOIT.

[freebullet]

I want to go down around the wall crossover the threshold and leap the hurdle in the next room. It's all the same thing, yet almost a page about it. Wow
Calling it a wall or hurdle would be referring to it as more of a limit than calling it a threshold.

I would rather hear more about the chrono than what to call the rpm thresallurdle.

[357maximum]

Freebullet...semantics....some of us have been arguing about them for years......you trying to ruin our fun?

[btroj]

If it weren't for semantics we would all agree and that would make for a boring forum.

Sometimes those little differences make all the difference in the world

[MBTcustom]

To Goodsteel.

a few things to ponder about why no solid info from those who may be skeptical.

Leaping the rpm hurdle is no small task in many cases. To quote someone else, it isn't rocket science but it does require some attention to details and some work.

Say a guy decides to try 2 bullets, 5 alloys, and 2 powders. He shoots 4 five shot groups per range session, two each with a couple loads.

That is now 20 different combinations but we need to look at working up a powder charge. Say we try 10 charges with each powder. We are now at 200 combinations, 100 range sessions, and 1000 bullets. I would call this a minimal effort, good results may require more permutations. As we shoot and learn we may alter the original plan.

those bullets need to be cast, heat treated, and aged to get consistent results. That takes time. Lots of time. Some alloys when air cooled may need 3 months of more to settle down.

What is the point of all this? That good, solid testing takes lots of time, bullets, and powder. Those 100 range sessions need to be on days with decent weather. If I can shoot 30 weeks per year with weather that makes for good results, not too windy or hot or freezing, the. I may need a few years to get the results in.

Anyone expecting any sort of solid evidence of anything needs to realize that time is a critical factor. Sound study takes time, a plan, and execution. Shooting a few loads doesn't prove a damn thing.

Who knows, in a few years we may be able to have a good discussion on how to leap the rpm hurdle. We can't do it now because the results aren't in. Heck, I don't even have the bullets cast yet.

Yep, good science is a slow process. It takes dedication, record keeping, and a plan. Anything less is just supposition based on a single result. We also need to keep the absolute bane of science out of the equation- bias. Anyone who has truly studied science knows how easy it is to let bias creep into results. This leads to inappropriate conclusions being drawn.

Now do you see why no data has been posted?

Brad,
That is the closest thing to a real post I have seen you make in some time. I agree with you wholeheartedly, right up to your concluding question.
The claims that this is able to be done by anyone, at significantly less effort than just handing your rifle to a gunsmith, breaking off a few C notes, and enjoying high-"ish" FPS, leads me to believe that it must not be as hard as all that.
Of course, if in reality, if this "perfect storm" is as you say (and I find much more likely) is very difficult to attain, and will cost you more in time, bullet molds, and components/brass, than any custom rifle build, then it boils down to which is capable of more accuracy.
Say the goal is 2800FPS with MOA accuracy so as to allow engagement of targets out to nearly 1000 yards.
One method that has been claimed add nausium, is to make the 1000 yard crawl over broken glass, via the flaming hoops of fire, and traversing the crocodile laden river of acid, till you arrive at a place where sweet fruition is realized with any janky old mil-surp with any twist.
Got it. I love the idea.
Larry is just offering a much more reasonable alternative to achieving that goal:
Spend a few hundred bucks and have your rifle rebarreled to a slower twist and do what Larry is suggesting in this thread. No ten years throwing powder primers, lead, money and time down the toilet like it was free. No butt kissing extraordinaire. No standing on someone else's experience (that cannot conceive of, or allow a less expensive option). Just use what you've got and rock on, under the RPMTH.

Personally, I want to do both, and I'll settle on whichever one is more accurate. Since Larry asks nothing and gives information freely (like what rifle, what range, pictures of real groups (and different groups at that. Not different pictures of the same group. "Ahem") graphs, clear explanations, and unbiased references that are taken in context.)I'm going to go this way for now.
Larry's method is so well written and laid out, It won't take me (or anyone with any rifle) long to put it into practice, and experience what is capable from my bench.
It's cheap, effective, and anyone who can read can git-er-did pronto.

By the same token though, I have not disregarded what I have been told might be possible if I am well healed enough in time money, components and patience.
Unfortunately, certain people have been swearing to high heaven and low hell that this can be done in any rifle since the mid 2000's, yet have not produced a clear argument in public in that entire time. You would certainly think that all that effort would be based on something but sadly, any sort of convincing argument to the contrary (sorry, trolling, vague allusions, carrots on a stick, rabbit trails, and hatred don't count, and would not be accepted by anyone of higher learning or education) have not been forthcoming.

So regarding your final question, I certainly do not see how in ten years, none of the people who argue so vehemently against the simple, cheap and effective method that Larry has laid out here have managed to produce a single thread or post that comes even close the level of professional communication that Larry has demonstrated here. It's truly a mystery.
Even if one decent irrefutable group had been shot and posted over and over and over, it wouldbe something but there is nothing of the sort.
Strange!

[btroj]

Why do that which is easy? That doesn't teach us anything. It doesn't further the knowledge. It doesn't fulfill a basic human inquisitiveness to learn.

I would rather fail trying the difficult that stick with the easy.

I always told my daughter that accomplishing the easy isn't very rewarding because it is easy. It is in accomplishing the difficult that we learn about ourself.

From what Larry is saying anyone can shoot well with a 16 twist barrel but it takes a truly accomplished caster and shooter to do so with a 12 twist.

Which do YOU want to be? I know what I want and it certainly isn't to take the easy way out.

[btroj]

As for those who say it is possible they have posted here. People just refuse to believe them. Well, some people do.

Just because you haven't seen it with your own eyes doesn't mean it isn't possible.

[MBTcustom]

Why do that which is easy? That doesn't teach us anything. It doesn't further the knowledge. It doesn't fulfill a basic human inquisitiveness to learn.

I would rather fail trying the difficult that stick with the easy.

I always told my daughter that accomplishing the easy isn't very rewarding because it is easy. It is in accomplishing the difficult that we learn about ourself.

From what Larry is saying anyone can shoot well with a 16 twist barrel but it takes a truly accomplished caster and shooter to do so with a 12 twist.

Which do YOU want to be? I know what I want and it certainly isn't to take the easy way out.

Because people have lives that don't revolve around shooting. Because people have limited money with which to buy components, and the prospect of just blowing what they have in order to find something that might be there is not an option, especially when they have an option right in front of them that will work just great for much less outlay (you know: so they can get back to actually shooting groups).
Because people have limited time such that one range trip every two weeks without fail is pushing it.

Which do I want to be? I want to be the guy that shoots tiny groups at long range with cast, and I really don't care how I get there as long as I can do it while I'm still young. LOL!
That's the object here. If you really believe what you are saying, then I expect you drive a horse drawn buggy to work everyday yes? LOL!
That's the way I see shooting high velocity the other way. I want to do it, but it's for the novelty of knowing how. Seeing as how I get all my gunsmithing done for free it really makes waaaaaaaaaayyyyyy more sense for me to go with slower twist wouldn't you say? Double whammy! It's cheap and then it's cheaper!

[bnelson06]

Because people have lives that don't revolve around shooting. Because people have limited money with which t obuy components!

I say we start a collection and I can devote all my time to this quest. A few dollars from many goes a long way for one

[MBTcustom]

As for those who say it is possible they have posted here. People just refuse to believe them. Well, some people do.

Just because you haven't seen it with your own eyes doesn't mean it isn't possible.

Whatever. Heard that lament for months now, and I wouldn't' say they strained themselves. If they had put one tenth the effort into helping people with their point of view that Larry has, they wouldn't be so dangerously close to taking their "secrets" to the grave with them.
More people would believe them if they'd quit fighting all the time and post about what they are doing, instead of running off the people who do believe in them and want to learn (such as myself).
They sure have posted here though. You just have to eat the meat and spit out the bones. Never mind the fact that you have to dig through 25 trash barrels full of bones before you find a stale half eaten Twinky.
I have never said it was impossible. I believe it is. I said it was impossible for the people who claim to be capable of it to find the little button that operates the shutter, or climb out of the trenches and have a little fun teaching people instead of fighting with them in open forum.
It's not about believing in them or not. It's about getting them to teach instead of troll that's the real trick.
Look at the lengths Larry has gone to to explain his point of view in spite of all the trolling. He's kept at it in spite of all the naysayers and guess what? People are catching on! Had the people on the other side not been wasting their time trying to undermine any alternative viewpoint, they might have actually gained some ground on this forum. As it is, if they endure just one fraction of what Larry has had to, they fold up their kite and sulk off.
I really don't know what to say about that, but if you want to lose my respect, that's certainly one of the best ways.

[cainttype]

A firearm is a tool. It's as simple as that.
Knowing how to accomplish the task at hand with an inferior tool is never a bad thing. Knowing the best tool for the task is pretty high on the priority list, too. Using the best tool available for accomplishing the same task is just good common sense.
If HV using cast, while maintaing accuracy, is easier to achieve by using a slower twist...Where's the problem?
It would seem to me that anyone wanting to "learn" as much as he can about shooting cast at high velocity would consider that information as critical knowledge, even if they know it can be done with more difficulty using a less than optimal "tool".

[357maximum]

Because people have lives that don't revolve around shooting.

Preposterous and I do not believe it for a minute.....BS...liar liar.

Most of what you seek was posted here: http://castboolits.gunloads.com/show...f-a-good-rifle , just do not look for Larry style, take you by the hand and show you methods, not only are some unwilling to do such things...some people are simply not born with the ability to teach the way Larry does......believe it ...for it's true. Not everyone was born a teacher...accept that fact and do some work on your own.....the basic blueprint is there waiting for you, and there are several ways to skin a cat........accepting that a cat cannot be skinned in less than 5 minutes is not the way to a fur coat made by your own hands...,...... you could just go to the store and buy a coat too...always an option...your call/your money/your time/your goals. To each their own, but calling others names for taking a different approach...solves what exactly......not everyone comes here to gain notariaty or to teach a certain method to reach mediocracy...and no that was not a slam on Larry....to each to their own desires.


BTW.....I would have piotentially flagged a few of your posts in this thread when I was a mod...please lighten up Tim, this is nothing to pop a vessel over.....your best way to go fast may very well be to re-barrel to a slower twist....it is a good option....a certain one....some people do not like easy/certain....to each their own....you pays your money not I...so do what YOU want, but please do not so believing it is theee only way.


sincerely,
Mike

[freebullet]

so can i shoot a gas checked boolit without the gas check or not?

[frnkeore]

Larry says,

Thought you were done with me......oh well, it had been peaceful in your absence

.

No larry, It was you that said that you were done with me, in one of our past discussions. I said that I did not want you to leave the thread and ask that you stay and follow it through. You can look it up if you like.

You are fan of picking out a few examples from CBA matches where the RPM Threshold has been pushed up a bit, just as I've continually said it could be. CBA matches are shot with accuracy in mind BTW and not to push a naked cast bullet of ternary alloy as fast as we can with accuracy (the object of these test....remember?).

Match shooters are looking for the best accuracy that they can generate, no matter what RPM it is. They are ALSO looking for the highest velocity they can obtain, while doing so, to reduce wind drift as much as possible. It can go hand and hand.

You'll note that 90% of the HV shooters are using medium burning rate powers, just as the jacketed shooters are using.

For your "threshold" to hold up, at all, it needs to be with any powder, including Unique. Other wise, RPM is just one factor of MANY and that IS, all it is!

Your term "threshold" seem conveniant to me. I see so many times that you try to turn people away from 2000 fps loads in a 10 twist and use loads in the 1600 - 1800 fps range because 2000 fps is not in your "threshold". I say give them the oppertunity to try it and give them the best info you can to get them there.

Then you tell people like me that it's just "threshold" and it can be pushed up when I/we have conflicting factual results, trying to minimize the conflicting info. It's kinda like your trying to "have your cake and eat, too".

It sounds to me that you use it more as a limit because you're not able to exceed it and don't know what it takes to do so.

While I will agree with the others that you put in a lot of work doing your test and it might prove that each rifle has a level of accuracy with the given powder and bullets that you fed them. It doesn't prove that the 10 twist, isn't as accurate as the others at any given RPM. I really couldn't call it scientific at all. It would have to be a blind test, with the same rifle, same chamber, same barrel weight & lenght, with different twist barrels. Even so, it can't test HV w/o the proper chamber and throat design. If you know anything about testing, you know that the tester can make his preceived out come a reality and not relalize it, himself.

The following are more match results for fast twist HV rifles. As you know, the shooters use these loads as there best and can go even higher (how high, I can't say) with better than average accuracy, they aren't looking for a "threshold" or hunting accuracy, just the best they can get, if it happens above the "threshold" so be it!

That said, I can tell you the basic reason that the following shooters can do what they are doing. It's in the chamber and throating first, next, the use of linotype for bullets and their fit, powder and other things come as tuning ingrediants. Note the alloy, most match winners and records are set with linotype.

Standard chambers, just won't cut it! The neck, freebore and leade angle are paramount when it comes to accurate cast bullet shooting, whether it's slow, medium or HV.

In closing, let me say again......... If one person can do something, reliably, then ANY other person can do that same thing! This is not magic, it's knowing how to put the whole package together.

Tamaqua, PA

Bottiger, Jerry, Cartidge, 7mm BR - Barrel, Shilen 23" lg, 9 twist - Weight, 12.62 lb - Scope, Weaver 36x

Bullet, NEI 170, Nose .276, Band .285 - Alloy, Lino - Primer, Rem 7 1/2 - Load, Varget 27 gr - Vel, 2000 fps (160,000 RPM)

100 yd, May 2014, ave. four, five shot groups, 1.395 - June 2014, 100 yd ave. of four, five shot groups 0.774

Bottiger, Jerry HVY 196 7x, Nesika Shilen 1 deg. Weaver 12 Lb. NEI 170 L Lino- nose .276, band .285 - 27.0 gr Varget - 7 1/2 Rem - 2000 vel


May, 2014 Charlotte, NC


Galindo, Adolph, Class, UnP - Cartridge 30BR - Barrel, Lilja 22" lg, 8 twist
Scope, Leupold 40x - Weight, 22Lb. - Bullet, LBT 180 sp - Alloy, Lino - Nose .304, Base .310
Primer, Fed 205m - Powder Chg, 28.5, Varget - Vel 2100 (189,000 RPM)

Galindo, Adolph UnP 197 8x 100 yd, 193 2x 200 yd, 100/200 Agg 390 10x

Galindo, AdolphUnP 5 shot group, 0.469 100 yd, 200 yd,1.807 100/200 MOA 0.686

Galindo, AdolphUnP 10 shot group, 0.951 100 yd, 3.232 200 yd, 100/200 MOA 1.283


Lowther, Scott, Class HVY - Cartridge, 30 BR - Barrel, Lilja, 24" lg, 10 twist
Scope, Leupold 36x - Weight, 13.5 lb - Bullet, Accurate 311205 - Alloy, Lino - Nose .3005, Base .311
Primer, Fed 205m - Powder chg, 28.3 N133 - Vel 2100 (151,200 RPM)

5 shot groups (ave of four, five shot groups) 0.759, 100 yd, 1.532, 200 yd, 0.763, Combined MOA

10 shot groups (ave of two 10 shot groups) 1.587, 100 yd, 3.633, 200 yd, 1.699, Combined MOA

Lowther, Scott, Class, Production - Cartridge, 308 Win - Barrel, Savage 26" lg, 10 twist
Scope, Weaver 36x - Weight, 11.75 lb - Bullet, Accurate 310220 - Alloy, Lino - Nose .300, Base .310
Primer, Fed 210m - Powder chg, 27.5 N130 - Vel, 2000 (144,000 RPM)

5 shot groups (ave of four, five shot groups) 1.321, 100 yd, 200 yd 3.081, 1.431 Combined MOA

10 shot groups (ave of two, ten shot groups) 3.242, 100 yd, 200 yd, 4.322, 2.701 Combined MOA

[357maximum]

so can i shoot a gas checked boolit without the gas check or not?

Has Carpetman been re-born???...RAY IS THAT YOU, boy you have been missed round here, got any spare gubmint cheese to share?

Yes you can shoot a gaschecked boolit without the check, but the world will go off it's axis and spin us all into space, destroying the atmoshere/stratosphere and then the sun will scroch the Earth into a Mars like landscape....do not do it please....we all need atmosphere.

[freebullet]

I'm doin it lol.

My name is Bruce and I do play with carpets.

[357maximum]

Bummer but I guess it all had to end sooner or later...oh well, maybe I can say hey to Ray in the spin cycle.

[Dutch4122]

357maximum is way to kind.

My rifle is a CMP Greek return Remington made 03A3 produced in May, 1943; with a brand new (in the wrapper & cosmo'd when I bought it) Remington made July of 1943 two groove replacement barrel. Barrel was installed by Badgeredd. As of this date the barrel has had only 103 rounds fired through it of the following load and no other:

Bullet Design: RCBS 30-180-SP (Late version, bore riding nose)
Actual weight lubed & checked: 190 grains

Cast of an alloy that is: (according to Badgeredd's alloy calculator)

92.35% Pure lead and other trace elements
3.73% Tin
3.5% Antimony
.22% Copper
.20% Arsenic

(Note: This is a copper enhanced alloy, and not the type of alloy that the OP used in the testing he has presented in this thread)

The easy way to mix this alloy is to follow this simple recipe of 8 lbs. Clip On Wheel Weights, 1.5 lbs. of Pure Lead, and .375 lbs. of Rotometals Grade 11 Babbit for a 10 pound pot. Double the amounts for a 20 pound pot and quadruple the amounts for a 40 pound pot, etc. Here's a hint, don't assume that your soft range scrap is in fact pure lead that's ok to use in this mix, it probably isn't. Use what this recipe calls for, don't deviate. There are enough variables to deal with in Clip On Wheel Weight alloy as it is. No need to have the other components skewed.

Bullets were water dropped from the mold into a five gallon water bucket. They were allowed to stabilize for two weeks, BHN was 28, sized/checked to .310" diameter and lubed with MML + 5% Soap. My mold casts a bullet nose that is .302" diameter using the above alloy from my mold.

The load itself is as follows: (loaded and shot as projected in Quickload)

46 grains of IMR-3031

CCI #200 Large Rifle Primer

54,000 psi / 100% powder burn / muzzle pressure = 7,849 psi

5 shot average over the chronograph is 2,510 fps. I was hoping to match the U.S. MkI ball load which was a 175 grn FMJ Spitzer at 2,600 fps. However, given the accuracy potential this load is showing I'm not going to quibble over 90 fps, especially since my boolit is 15 grains heavier.

Ok, so here's the deal with this rifle and load. When I say 103 rounds I mean that is the absolute total number of rounds which have ever gone down this barrel, period. The barrel has only ever fired this particular load. The 1st round went down the tube at the end of May. First 5 shots fired went into 3" at 100 yards with one flier I believe to be the very first shot opening the group from 2.5" to 3" Either way, that is within acceptable U.S. Ordinance accuracy standards for these rifles as they came off the line at any manufacturer. I was shooting that day with Castboolits Member "Mostlyonthepaper" and he can verify this plus I have the target saved. Minor sight adjustments were made and after that the rifle has not been put through any serious target work since; just pounding rocks and steel at 250 yards. The plan has been to give it about these 100 rounds of shooting for the bore to season with lube before getting serious on paper. While shooting at Badgeredd's place on June 8th the rifle seemed to be shooting better as the round count rose. 357maximum was spotting for me through 10x binoculars and advised I was hitting the same 2"-3" spot on a rock @250 yards repeatedly before I split the thing.

So, the load shows some real promise out of a 24" barreled 03A3 with issue receiver sights. Enough to warrant some real testing.

dtknowles -

Right off the bat I will tell you this. Bullet fit is king. Also, my rifle has a 24" barrel and yours has a 22" barrel. I believe, based on my experience, that keeping muzzle pressures below 8,000 psi is very important for even usable accuracy. Your barrel will produce higher muzzle pressures than mine with the same load due to the fact that it is shorter. Find a bullet in the 200-210 grain weight range when cast out of this alloy that fits your rifle properly when chambered. Start out at 43 grains of 3031 and work up. If you have the alloy, lube, and fit right I think you could find a good load.