Firearms Working Pressure

[Gun Smith]

Every once in a while we'll get a question about rifle working pressures. Here is a list from 1952:

Winchesters: M. 54/70 is 55,000 psi.
M.71 is 45,000 psi.
M. 86 is 39,000 psi below ser.# 126,000.
M.86 is 45,000 psi above ser.# 126,000.
M. 94 is 39,000 psi.
M.95 is 45,000 psi.
Others:
30/40 Krag is 43,000 psi.
Marlin 336 is 39,000 psi.
Savage 99 is 40,000 psi.
Lee Enfield is 45,000 psi.
Springfield is 50,000 psi (Springfield Armory above ser. #800,000).
Mauser 98 is 55,000 psi.
Enfield is 50,000 psi.
Mauser 1888 is 50,000 psi.
Mannlicher- Schoenour is 45,000 psi.
Remington 721/722 is 60,000 psi.

[AJMD429]

Cool list.
I'd be curious as to some of the 'modern' guns.
I'd think something like a Ruger No1 would be pretty stout.

[Gun Smith]

I found a couple of interesting bits further along in my records from this period to add to the above post.

One pertaining to the Jaranese Arisaka military rifles. The early prewar 6.5 and 7.7 MM rifles were proofed to about 75,000 psi.

High serial number Springfields, above 800,000 could not be broken with the highest proof loads that could be made up for this caliber, namely 125,000 psi without failure.

[winchester1886]

Gunsmith that is very interesting where did the list come from, if you don't mind me asking.

[Old Time Hunter]

Well, I for one, am impressed!

Most surprising to me is the Mauser 1888@50k psi.....never heard of a Mauser 1888, could it possibly be a Commission 88? Still 50k is pretty stout for a rifle designed in 1888. Wonder if the bolt design influenced Winchester on their 88? (yes I know one is a bolt and the other a lever)

[Gun Smith]

My last couple of postings come from my old loose leaf note book from my Gunsmithing instructor at Lassen Junior College. That is where I received my basic training in 1953-55.
I looked back at the list this AM. It does say Model 1888 Mauser. But, it could be a typo, or mistake, as this data is from a typed copy of the course. I'll check it out.

EDIT
Yes, this Model 88 appears to be the "Commission" model to replace the M71/84 due to the French bringing out their first military smokless powder cartridge in 1888.

[Mike D.]

The listing of only 6K difference between the pre and post-126000 serial numbered Model 1886s has me a bit "cornfused". I believe that the original intent was to differentiate between the ordnance steel and nickel steel barrels. The NS barrels were first offered around 1895, but were only available on lightweight rifles. By 1902, when serial number 126000 was reached and the .33 WCF was introduced, the NS barrels were much more prevalent, but remained standard on only the LW rifles, with other calibers and standard rifles on special order only. The so called BP caliber guns carried the older type steel barrels. Granted, the frames were strengthened, but the barrel steel remained mild until the older calibers were dropped around 1910-11. Standard .45-70, .45-90, and 50 EX rifles remained in production until 1919. With few exceptions, these guns wore non-NS barrels.
Were all rifles post-126000 capable of 45,000 PSI? I don't think that I would go so far.

[Gun Smith]

Hi Mike, my old list only mentions 126,00 as the change, and there may be a reason for that. Is it possible Winchester may have used up the receivers on guns that were chambered for the older original BP calibers after the change at 122,000, and my list may account for the that. Do you know if there are any guns out there with case colored receivers after 122,00? Madis says Winchester had trouble color case hardening the new receivers.

Madis says 122,000 is where the change in action strength changes. He also says 1895 for the nickle steel barrels as you mention.

Madis' book was 9 years in the future from my list.

[KWK]

Being from 1952, these pressures might be more of a "CUP" rating.

[Leverluver]

Being from 1952, these pressures might be more of a "CUP" rating.

I agree. 52 was long before "psi" as in in piezo even existed. The "numbers" were called psi because that was all there was at the time. Even so, a lot of those numbers don't pass the smell test as CUP either. Nice snapshot at a moment in history but I wouldn't bet money on the majority of them.

[KWK]

Piezo pressure measurements go back to WW-I, on an experimental basis. By WW-II they were considered the gold standard, but because of the expense, the crusher held on for several more decades.

[Leverluver]

For military, I would agree. For commercial, I doubt that piezo was used industry-wide before the late 70s. And a lot of rounds are still not piezoed. Just try to get H.P. White Labs to piezo a 45-70.

[KWK]

I think you're right about industry picking up the piezo. Maybe even '70s was a bit early.

As for White & the .45-70, perhaps they don't see the value in investing in a piezo barrel. I suspect the crushers are accurate enough at pressures in the 20's and below.

[Leverluver]

H.P. White Labs doesn't do piezo on the 45-70 because the SAAMI spec for the 45-70 is still in CUP. That was never changed and they only test according to SAAMI. If a cartridges spec is in piezo psi, that is what they test it in. They are the longest standing testing lab in the USA. They go back nearly 80 years.

[KWK]

Maybe they need to get a copy of the current SAAMI spec's. My print copy (1992) has a piezo standard for the .45-70, namely 28 ksi. Several other old cartridges are (were) only in CUP, though, such as the .44-40.

[Leverluver]

My mistake. That's what they told me when I asked about them running some for me.

[winchester1886]

As far as the 1886 goes I thought that 122000 was the number that they changed at, but the only thing that changed was the barrel, that the old action was strong enough to handle smokeless powder, this is backed up by rifle number 21444 an 1888 production, page 331 of Madis's book this rifle was sent back to Winchester and rebarreled to 33wcf, so they thought the action was strong enough for the smokeless load.
I always thought that if the number was above 122000 and the action was blued then the rifle was a smokeless rifle, maybe not ???? also that the Black powder rifles were rated at about 26000 psi and the smokeless at about 40000- 42000 psi maybe wrong again, so I sure hope there is someone out there that knows a lot more then me and can set me straight.
I have had three 86's with serial numbers above 122000, a 33 wcf serial number 13278x no proof marks, barrel marked nickel steel especially for smokeless powder, a 40-82 serial 13759x proof marked, a blued action and no nickel steel markings on the barrel, and one I have now in 33 wcf has been rebarreled with a genuine Winchester barrel, the serial is 15376x, one proof mark on the action, two on the barrel which I believe is to indicate that it is a genuine Winchester rebarrel, it has the nickel steel marking, the normal Winchester markings on the left side of the barrel, and also on the left side MADE IN U.S.A. and on the right side - MODEL 1886 - just love this rifle.
Can anyone tell me is the 40-82 a smokeless powder rifle I thought with proof marks it was ???

[awp101]

Lee Enfield is 45,000 psi.
Enfield is 50,000 psi.

Interesting...I wonder if they are considering the SMLE as the Lee-Enfield and the No4s as just Enfields?

Yes, the "Mauser 1888" is the 1888 Commission Rifle. From what I gather, any old German rifle was considered a "Mauser" regardless of the designer or manufacturer, kind of like Kleenex. I even see it now on Mauser forums where someone asks "Please ID this old Mauser found in the attic of my "fill in the relative's" house" and it turns out to be an Arisaka or Carcano.

FWIW, the MP40 subgun has always been called the Schmeisser but Hugo Schmeisser had nothing to do with it.

[KWK]

My mistake. That's what they told me when I asked about them running some for me.

No, their mistake. Either the guy wasn't aware of the standard, or White simply didn't want to invest in a piezo set up. SAAMI has both a CUP and a piezo rating (both 28,000 psi, nominal), so White can test in either system and meet the rules. I'll note that Hodgdon has .44-40 data in piezo, even though SAAMI has (had?) no spec for it. From what little information I have, CUP and piezo are little different at lower pressures, so it wouldn't be worth White's money to have an additional piezo barrel made up.

[Gun Smith]

awp101,
On my list the U. S. WW1 1917 Enfield is the "Enfield", and the Lee-Enfield SMLE is the other.

For anyone.
All the pressure data I used those 55 odd years ago was the old standard "cup" measurement. When was the new standard SAAMI adopted?

[Gun Smith]

Type in Cartridge Pressure Standards on the web, there is a site comparing Piezo to copper crusher pressure methods for many calibers. Interesting reading.

[Mike D.]

Winchester rated their Nickel Steel barrels at 100,000 PSI(CUP?) shortly after their introduction. Later manufactured 1886s are every bit as strong as the modern made copies. Winchester went to their Proof Steel barrels in the mid 1930s, a metal that had both superior strength and ease of boring/chambering. Nickel steel barrels were notoriously difficult to bore and hard on machinery.

[awp101]

awp101,
On my list the U. S. WW1 1917 Enfield is the "Enfield", and the Lee-Enfield SMLE is the other.

Aha! The P17 totally slipped my (rapidly failing) mind...