Reaching out to us old timers to see if anyone knows what type barrels (actual revolver or unvented test barrel and length) the major ammo manufacturers (Rem/Win) used pre SAAMI when testing the velocities of their factory revolver ammo?

Thank you

An interesting question, but I doubt many who would have firsthand knowledge are still alive. The use of a revolver for such factory testing is not a good idea, as has been well documented, different revolvers having the same barrel length can produce significantly different MVs when firing the same ammunition. That will not be satisfactory for quality control purposes, which is the main reason the loading companies do MV testing. Consistency in test methods is essential.

Some reloading manuals will list the guns used for velocity testing of their reloading recipes.

I don't have firsthand knowledge, but l do have some documentation on

357 magnum factory and hand loads tested by H P White Labs after WWll.

They used actual 357 magnum handguns of varying barrel lengths and

results measured in PSI.. As l remember the highest reading was 36000psi

on a factory load...

I also might add that I think back then they used the CUP method for pressures.

PSI was invented some time later.

You do realize SAAMI started in 1926?
Anyone who was old enough to work (16) in 1926 would now be 107 years old if they still survived.


"The Sporting Arms and Ammunition Manufacturers' Institute (SAAMI) is an association of the nation's leading manufacturers of firearms, ammunition and components. SAAMI was founded in 1926 at the request of the federal government"
SAAMI | Sporting Arms and Ammunition Manufacturers' Institute

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Science plus Art

Did some searching.......

All pressures up to 1960 were by way of the crusher system giving out CUP for pressures.

The transducers needed for the PSI pressure testing was not invented until the 1960's.

However one 1987 Speer manual only listed pressures in CUP........... just to confuse the issue
since the CUP system is old style and trying to be phased out in manuals, of today.

Some of you who have been reading HANDLOADER for a long time may recall a noteworthy 1972 article by a Speer ballistics guy, Bill Caldwell. Much of the material is dated, but some of it may be relevant today. Of course, the CUP and LUP methods of measuring were used in those days. Regardless, Caldwell found that pressures in revolvers were surprisingly somewhat higher than in unvented test barrels. He has hard facts based on test work to back up his conclusions.

Even in 1972 (as mentioned in the article), it was known that "judging" high pressure was particularly difficult in a revolver as there were few reliable indicators, primer appearance being the least reliable.

Found the publication...titled-Volume 1 of Reloading lnformation

from The American Rifleman.

National Rifle Association Handbook No.1 seventy-five cents

Julian S Hatcher, Al Barr and the H P WHITE CO.

CHARLES L. NEWMANN..

Copyright 1953...Also have Volume TWO..

V 2 written by Al Barr. The H P White Co.

Jerald Tisdale, ELMER KEITH, Ben Hardaway..

Copyright June 1953

ALL PRESSURE READINGS IN BOTH VOLUMES ARE IN

''POUNDS---PER---SQUARE---INCH''

I sent these to a Forum member some years back and allowed

him to copy them...I think he lived in Knoxville TN

Need to correct a statement in my first post...For the Pressure readings

in 357Magnum they used a Smith&Wesson 8 3/8'' factory pressure barrel

.346'' land dia.-.356'' groove dia.- twist one in 18 3/4 inch..

Highest pressure handload was ''41,470 P S I''. H&G No.50 wadcutter..

Highest ''Commercial Load'' pressure was ''43,160 P S I'' 158gr

Most accurate handload powders listed were UNIQUE and 2400//

Some things(good powders) never change :-)

From what I remember reading about the PSI vs CUP back int he 70's was that CUP at that time was more consistent lab to lab and between equipment, it was more trustworthy, more repeatable, even if there was a desire to move to PSI. Something something to the effect that the techn wasn't there but it could change in the future, and considering the book I was reading was a sold as my car, I suppose much has changed in nearly 40 years. Another thing that has changed is gun writing went from "smart" to "mark" borrowing on terms from pro wrestling, insomuch that "The Rifleman" used to have a lot of thorough technical articles and science and now is mostly advertisements and everything is written in pretty dumb terms meant to make all products and loads look good.

Where this leads to is, back in the day everything from Rifleman articles to truck manuals gave you every single technical spec you could want, and if you asked the authors and companies, they would send you more. Today the specifics aren't presented , advertisers and companies want to steer you towards image instead of numbers and qualities, and a new truck manual is just 200 pages of "Don't do this, it will void your warranty". It seems that you could get more casual information about the lab and its work back in the day, and nowadays all you can get are company lines and spokesmen. I like the shooting sports, and nothing against the fine professionals who compete, but I don't give a damn about your sponsored shooter sponsoring your product any more than I'm going to buy General auto insurance because of Shaquel O'Neil.

Another tl;dr rant, but it would be fun to see the progress of the machinery that goes into lab testing, if you can even find it.

My mistake, I thought SAAMI established their standardized barrels and lengths commencing after 1972?

Wonder if SAAMI had barrel standards (length and type) used in velocity tests prior 1970?

When it was a far better magazine, the AMERICAN RIFLEMAN had a "technical staff" that contributed to the more meaningful articles. I don't know when they did away with the technical staff, but it's been a long time. Much of the current material reflects that poor decision.

The NRA had more time and money to do research and shooter advocacy before they had to use so much of both to resist the anti-gun nazis. Some of the generation just ahead of me got a lot of their technical info from them. Shooting was a part of young peoples up-bringing and common sense education. I'm sorry the world has changed so much.

__________________
dd884
JMHO-YMMV

It is impossible to measure chamber pressure using a revolver. Pressure testing must use a barrel and fixture designed for that purpose.

"From what I remember reading about the PSI vs CUP back int he 70's was that CUP at that time was more consistent lab to lab and between equipment, it was more trustworthy, more repeatable, even if there was a desire to move to PSI. "

Nope. Not even close. Prior to the advent of the piezoelectric pressure gauge for ballistic pressure testing in the 1960s, the copper crusher method was the only way it was done. The technology did not exist to use anything better. The copper crusher method was even used for chamber pressure measurement on artillery pieces. The "Copper units of pressure (CUP)" wasn't a pressure measurement at all. It was a very crude analog to "average" chamber pressure. The piezo gauge actually does read in psi directly (and also instantly and accurately), and has a much shorter time constant than the copper crusher. There is really no good way to compare CUP to psi from a piezo gauge, but as a rough approximation to peak chamber pressure, the actual peak chamber pressure will be around 20% more than the corresponding CUP. I doubt if any ammunition manufacturer in the civilized world today still uses the copper crusher method for pressure measurement, but SAAMI still administers the standards for it.

Walt...Please read post #9. ln it l stated a factory Smith&Wesson

pressure barrel of 8 3/8'' was used...Reading further it says they used

''Winchester copper crushers with variation in length controlled to .001 inch

and Winchester tarage tables''... Reading further on the net l see there is

still quite a bit of dependence on the CUP methods... Posting the info

from this old 64 YO manual PROVES that PSI has been used for a good while..

l will say that looking thru the loads in these old NRA handbook and

comparing them with Speer 14 and Hornady 9 both are pretty CLOSE.

0ften the newer Speer & Hornady being HIGHER!! This old manual used

the finest equipment available from Winchester and Smith&Wesson..

They did it in the most respected ballistics lab of the time. HP WHITE..

l think they are still in business too...imho- New does not always mean BETTER

I have a truly ancient NRA handloading manual and in the back they have a Mann rest. Basically a real heavy cast iron V block. The barrel is about 5" in diameter and either a mauser or springfield action was screwed on this monster. the barrel was allowed to move on its cradle in the v block. The article was about testing 45 acp loads hence the use of a springfield or mauser action. Frank

The copper crusher method does not, and never did, give pressure results in psi. Many confused psi with CUP, and that is where the confusion occurs. No manufacturer in their right mind would use the copper crusher method today, as it is imprecise and very difficult and time consuming to use. I have been in the ballistics labs of every major U. S. manufacturer and exactly NONE use copper crushers.