doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com (OT) 6,2mm/52 marked old German double

Raimey,
Thanks for going trough your notes to present this interesting data.

Sliver,
Thanks for letting me know.
Is your Fukert drilling self-cocking hammer type?

With kind regards,
Jani

Yes.

Cool. I've always liked that system. It's on my wish list. - Jani

ejsxs:

I know that article like back of hand but didn't recognize the reference right off. I've been curious if the drilling is as difficult to open as noted in the article when all tubes have been fired. And would someone what to venture a guess as to what is on page 70, the last page of the article:

A box of 10 6.5X52R cartridges by PATRUUNAA with "(25-35)" below "6.5X52R".

Jani:

Glad to look. Now that I've looked a bit more the date looks to have narrowed to 1922 - 1924. Mind you there are examples from 1927 & 1928 with just say a "7.8" mm stamp, but the stamp of the pre-bore diameter over the cartridge length surfaces in the early 1920s.

Kind Regards,

Raimey
rse

Raimey,
My G.L. Rasch is marked 10/27 so I would think it was proofed in October 1927.
-Jani

Raimey,

My Eckoldt opens up without help after firing the three locks though it does a little faster when two locks are fired, but the difference was not noticiable by me until I read the article. Yes the photo of the PATRUUNAA cartridges in page 70 is quite telling and settles the argument IMO.

Regards.
EJ

My Miller & Val Greiss hammer drilling is marked 8.8mm/72 (The R is not marked). Dimensions via a cerro-safe cast are proper for the 9.3x72R. An unmarked hammerless drilling proofed 1907 (So Marked) is stamped 172.28/59. Except for the 1mm length difference chamber is proper for the 8x58R Sauer. I have also seen this round labeled as the 8x58½. 172.28 is .300" cal, which seems tight for even a .318" bullet, especially the steel jacketed one for which it is proofed. I think this simply meant it accepted the 172.28 plug gauge but not the 156.14 one (.310"). I do not recall present bore dia, but it was real close to the .310" & groove dia actually measures about .320" (neither .318" or .323") Both of these markings of course denote bore dia, not bullet dia. I have not really examined a lot of German made sporting rifles, but all which I have had bore dia & case length marked by the proof house.
For some 50 yrs I have been led to believe the .25-35 & 6.5x52R were the same thing. As has been noted it is a different dia than most other 6.5MM rounds, being a .25"cal. This is a bore size which is not common in Europe. I had been of the opinion that some makers had adopted the Winchester round & simply given it metric designation. I believe they likewise called the .30-30 the 7.62x52R (7.62mm is incidently .300" not .308").
Does anyone have SAAMI Specs for the pressure of the .25-35 Win. I do not believe it will be anywhere near 44K psi.

2-piper,
This was published on another well known forum on 05-08-2009:
"The older SAAMI specifications for 25-35 were 40,200 Cup.
It appears the current SAAMI specifications for the 25-35 are 37,000 CUP.
(...)
It does appear the pressure specifications for the 25-35 are held lower in deference to the older rifles which are still in use for the cartridge."

With kind regards,
Jani

Miller:

Actually, it is. Seems a lot of people don't understand the standards though.

Keep in mind, CIP protocol has never been the same as SAAMI's. Same pressure, different numbers, because the measurement systems have always been different. Again, CIP, for BOTH old, obsolete crusher standards and current piezo electric transducer standards, has always required use of a drilled case, which SAAMI has never used, with predictable results. Thus, SAAMI crusher protocol and CIP crusher protocol won't give the same results when testing the same cartridge. SAAMI piezo and CIP piezo don't either.

The .25/35 Winchester, for both SAAMI and CIP purposes, has always been loaded to slightly lower pressure than it's contemporary, the .30/30 Winchester, but they're close. SAAMI apparently hasn't restated .25/35 MAP from crusher yet, but it looks like it should be about 41,000 PSI, SAAMI protocol, which is about the same as CIP current standard, 44,236 PSI.

Here are the old crusher and new piezo SAAMI and CIP standards for comparison. These should help understand the common differences.

.30/30 Winchester:
SAAMI: 38,000 CUP (old crusher, SAAMI protocol)/42,000 PSI (new piezo, SAAMI protocol)
CIP: 41,000 CUP (old crusher, CIP protocol)/46,412 PSI (new piezo, CIP protocol)

.25/35 Winchester:
SAAMI: 37,000 CUP (old crusher, SAAMI protocol)/41,000 PSI?, new piezo, SAAMI protocol)
CIP: 39,000 CUP (old crusher, CIP protocol)/44,236 PSI (new piezo, CIP protocol)

6,5X52R:
CIP: 31,908 CUP (old crusher, CIP protocol)/35,534 PSI (new piezo, CIP protocol)

Not hard to follow.

We are lucky, even blessed to have someone here who does!

JC