Shooting .308 in a 7.62 NATO milsurp?

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K_Roc

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Is it safe to shoot .308 Win in a 7.62 milsurp?

I have read before (I think on surplusrifle.com) that it is not, but I just found this online dealer who is selling 7.62 Israeli Mausers and advertising the caliber as .308:

http://www.collectiblefirearms.com/RiflesMauser.html

I understand that the chamber pressure of .308 is much higher than 7.62, but is the Mauser action up to this challenge?

How about an Enfield in 7.62?

-Kevin
 
The answer is not a clear "yes or no" - it depends on the combination of ammunition and firearm.

Chamber pressure is one consideration, but headspace is also important. Military 7.62 chambers may be cut on the large side, and the resulting headspace may be excessive for some commercial ammunition, leading to dangerous results such as case separation, and so forth. Note that the combination of a "hot" commercial load with thinner commecial brass in a sloppy milsurp chamber is an obviously dangerous combination.

Still, there are many milsurp rifles that can safely digest commercial .308 without any problems. I don't know specifically if the Israeli Mausers would be okay with commercial ammo, but someone on the board will be able to provide an informed opinion.
 
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Those rifles were possibly either 7.92 mm yugo post war purchase later arsenal finished and rebarrelled for 762 nato or purchases of later manufactured 762 FN Mausers as replacements. After the 48 war the Israelis decided to manufacture their own weapons. UZI was one of the first and the FNs were copied/repaired at this facility. When mass purchases were made in a new calibre such as the FNs then eventually reservists were issued the mausers which were eventually rebarrelled. Many were sold out of service and used as target rifles by units, some had 30 cal browning barrels utilised and turned down to fit. These should be safe to fire and I have fired a similar one here a few years ago. Fun it wasnt but a bit of history nonetheless.
 
The Israeli Mausers seem to have nice tight chambers. I've got one and sold another - both worked fine with factory ammo. The one I shoot is probably my most accurate milsurp. Brass fired in it only moves the shoulder ahead about .002 compared to new brass.
Most of the concern about factory ammo is in semi's - even with similar velocities, different powders could cause higher gas port pressures.
I've chronyed both surplus and factory, the surplus was slightly hotter than the factory.
The pressure info below is not as scarey as it looks - 62000 PSI is equivalent to 52000 CUP

308 Headspace Gauges GO: 1.630" NOGO: 1.634" FIELD REJECT: 1.638".
.308 Winchester
Headspace Gauges
GO: 1.630"
NOGO: 1.634"
FIELD REJECT: 1.638"

CARTRIDGE DIMENSIONS MIN MAX
SAAMI .308 1.627 1.633
GOVERNMENT NATO 7.62 1.630 1.633

CHAMBER DIMENSIONS MIN MAX
SAAMI .308 1.630 1.640 (normal factory limit is 1.636) GOVERNMENT M-14 7.62 1.6355 1.6385
GOVERNMENT M-14 Match 7.62 1.631 1.633 (individually cut and non-interchangeable)

SAAMI .308 Winchester chamber pressures
MAP: 62,000 psi, MPSM: 66,000 psi
Minimum Proof Pressure: 83,000 psi
Maximum Proof Pressure: 89,000 psi
ANSI/SAAMI document Z299.4-1992,
"Pressure and Velocity, Centerfire Rifle Sporting Ammunition"

Pressures for .308 are as taken by current SAAMI procedures and are actual pounds per
square inch as measured with a piezo-electric transducer


7.62x51 NATO
US Army Headspace Gauges
GO: 1.635"
FIELD REJECT: 1.6455"

Maximum: 50,000 psi
Proof pressure: 67,500 psi
ARMY TM 43-001-27

Pressures for 7.62 are still taken in a copper crusher barrel and are recorded as psi because the DoD has not adopted the SAAMI designation of CUPs (Copper Units of Pressure).
 
AFAIK, you can't directly compare NATO pressure specs and SAAMI specs. One's measured in PSI and the other in CUP. Not sure which is which, but I know they don't correlate 100%

This I do know though: I've never heard an account of a 308/7.62 blowing up due to incorrect ammo type being used. I'm pretty sure the whole NATO vs SAAMI thing is a legal CYA excercise more than it is an actual safety issue
 
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