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Old November 7, 2013, 03:09 PM   #26
Paul B.
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"In my opinion, far too many reloaders let their ego's take control over safety; sometimes out of ignorance and other times out of greed. If I were the moderator of this thread, I'd lock it up."

That's what I like. Censorship. You don't agree so shut up.

Fact. The .257 Roberts is NOT loaded to it's full potential.

Fact. The purveryors of load data do not give full power loads for the .257 Roberts yet they give multi-stage load data for the Colt .45 and 45-70 that is appropriate for the various strength firearms chambered to those rounds.
Two of my favorite cartridges happen to be the .257 Roberts and 7x57 Mauser, both handicapped by lawyer proof load data.

This has absolutely nothing to do with ego or greed. It's like buying a Corvette ZR1 and turning off two cylinders. My several rifle in 7x57 include a Ruger #1A, Winchester M70 Featherweight and a custom Mauser. My .257 Roberts are a Ruger #1 B and Winchester M70 Featherweight. Every one of theos rifles can easily hold the pressures of say a .300 Win. mag. or one of the R.U.M.s. 60+KPSI. Some are 65KPSI.
The point is if the gun is capable of handling loads of that level, let us have the data. As at this time they do not, we have to work it up ourselves by the seat of our pants. I understand their stance. I once owned a beautiful sporter based on an 1893 Mauser. I knew enough to not push it very far. I know some noobie seeing the extra hot loads could use it and blow his fool head off. I just would like access to the data my rifle is capable of using.
Come to think of it; it wouldn't surprise me one bit if it came out that the guys who do the load work ups for manuals haven't worked up to the proper levels for their own use. Nope not one bit.
Don't mean to make anyone mad, just a statement of how I feel on the matter.
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Old November 7, 2013, 05:30 PM   #27
Bart B.
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Paul, what's the ammo industry pressure limit for .257 Roberts +P loads?

Is firearm strength the only issue for that limit?
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Old November 7, 2013, 05:30 PM   #28
Slamfire
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This thread is a total moot point for the OP but I love to pontificate, just like the rest. For those who are new to reloading it is best to err on the side of caution. For me, I have now spent decades studying materials, mechanics , and action design, so, through hubris, I think I understand enough to get myself into trouble.

Even though I am not part of the board, nor privy to their deliberations, it is obvious that SAAMI pressure limits were set considering the weakest link. That is the number of old rifles out there that could be chambered in that cartridge. Until you study late 19th century and early 20th century metallurgy, you don’t realize just how primitive the technology and inconsistent the materials of that period. Sure , some of the designs are excellent, some are still in production. But the manufacturing processes of the era stunk and the plain carbon steels these old guns were made out of are now called “low grade” and used for rebar. For decades Gunwriters have confused the issue, trumpeting terms as “old world craftsmanship” when shilling for import firms selling surplus weaponry. These guys don’t know a cold solder joint from a fatigue fracture but they do understand the selling power of the impressions of quality they create, even if they don’t understand steels, heat treatments, or quality assurance control.

Phillip Sharpe was an honest man, he had enough statue and intelligence to write, in 1936, about the risks of old guns:

There has been a great deal of improvement in steels, whether they be ordinary soft steels or various forms of nickel steel. No attempt with be made here to describe steels, as the subject would require and entire book. Thirty years ago, very little was known about heat treatment..

If you had a Winchester Model 1892 manufactured in 1905 and an identical model manufactured in 1935, assuming the original gun to be in perfect condition inside and out, you might place them side by side and notice absolutely no difference at firs glance. Careful study, however, will reveal that the later gun is manufactured better, with a minimum of tolerance, slap, looseness or whatever you may choose to call it. That, however, is the minor part of the of the whole thing. There will be little laboratory resemblance between the material of which the two gun are manufactured. Changes and improvements are being made constantly, and where changes in the quality of steel or the strengthening of certain parts through heat treatment are made, the factory rarely, if ever, makes any announcement. If these same Model 92 rifles were fired with a Magnum .38/40 load, it is quite possible that the earlier gun might go to pieces, while the later one would be perfectly safe. These facts must always be considered in handloading.


Complete Guide to Handloading by Philip B Sharpe. First Edition 1937, Chapter XXX, Magnum Handgun and Rifle Possibilities.

Mr Sharpe was born in 1903, died 1961. (No modern gunwriter has the background, education, understanding, that these Ordnance trained early gunwriters had about firearms.)

So for an older cartridge, such as the 257 Roberts, the pressure limits had to have been set taking into account the loads and proof pressures older actions were designed to.

All actions were designed to carry load. Just multiple the case head area by the maximum pressure, add safety factors, and that is how much load the lugs/receiver seats were designed to carry. Given a modern action, such as the M700, made of modern steels, that action can support more load, without permanent material deformation, than an older action made of plain carbon steels. So, for something like the 257 Roberts, given that this action was designed to support the load of a 270 Win, 30-06, 308, structurally, the action can support a 257 Roberts case giving the same load.

Obviously, modern actions are designed to support loads from cartridges over a wide spectrum of case head diameters.


What you find, in modern rifles, the brass case becomes unglued before the action reaches its limit, and then, all hell breaks loose. For modern actions, whether an action is weak or strong is in my opinion, more about how well the action supports the case. For endurance limits, that is, how many times the action can support the load without fatigue fracturing, that is a much more involved issue

The cautions that Bart B gives are entirely appropriate.

Quote:
Unless one has proper pressure measuring equipment, they're lacking the wherewithall to do that.

Cartridge brass typically starts extruding into chamber places where there's no support for the case at pressures starting at about 70,000 cup. I've shot dozens of 7.62 NATO proof loads in Garands and those cases look virtually identical to the same cases (by lot number) in its original M80 ball configuration; peak pressure from them's about 70,000 cup and then some.
Phillip Sharpe has a section in his book about how terribly inaccurate our traditional means of pressure inspection are at estimated actual pressures. Without pressure equipment, what pressures do you really know you are operating at? The pressure curve is exponential.

It is best to stay within the parameters of published data, and if you explore outside of it, you have to be real attentive to what you are doing. If you are getting fantastic velocities you also have fantastically high pressures, even if your case and rifle are not giving pressure indications.

I wonder why anyone “needs” to soup up the 257 Roberts or needs to improve it. What is wrong with a cartridge that pushes a 100 grain bullet at 2800 fps?







I do want to thank the forum member who helped me acquire his 257 Roberts brass. Without his assistance I would still be waiting for brass to appear at the gunstores.
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Last edited by Slamfire; November 7, 2013 at 05:51 PM. Reason: verb tense wrong
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Old November 7, 2013, 05:45 PM   #29
hgmeyer
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My Roberts in a beautiful '93 Mauser has accounted for over 40 deer in 40+ years. I like 100-115 gr bullets and have tried many over the years. Now I have not conducted extensive interviews with any of those deer. BUT, IT WOULD NOT HAVE DONE ANY GOOD. there were not able to respond.

Now, none were over 275 yards but none were launched at over 2700fps. I have a few other rifles to choose if I wanted, but I don't and I haven't for any anticipated woods hunting.

My point is that I don't need or want .25-06 or .257 Wby performance for what I want my .257R to do. And, it does it well way inside the envelope.

(every time I use it I have to thank my friend who passed away 30+ years ago... Thanks Tex, you were more than "right".... I do love the rifle)
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Old November 8, 2013, 10:17 AM   #30
Clark
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Quote:
Paul B.
Fact. The .257 Roberts is NOT loaded to it's full potential.
A decade ago on a forum far far away, a Paul B. wrote about "long brass life" as a measure of a load's utility.

That has stuck with me.

In 2012 I built a 257 Roberts Ackley Improved rimmed 1885 Win type rifle.

The Norma 7x57mm rimmed brass I used did not go to 80 kpsi as I hoped. It would only do 60 kpsi.

I shot 4 deer with 115 gr Nos Bal Tips at 3,050 fps, not 3,200 fps as I had hoped.
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