7.62 X 51 in .308 Winchester Bolt Action ???


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FMJMIKE
April 4, 2011, 10:37 PM
Can you shoot surplus 7.62 X 51 ammo in .308 Winchester caliber bolt action rifles ???

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Jeremy2171
April 4, 2011, 10:42 PM
yup...

Robert
April 5, 2011, 12:07 AM
308 and 7.62x51 are externally almost identical. The interior dimensions of the 7.62x51 are slightly different due to the general use of thicker brass. This means that a 7.62 case will hold a little less powder. The other issue folks seem to have comes from SAMMI and .Gov using two totally non interchangeable methods to measure pressure. CUPS =/= PSI. They are totally different and are not equal at all. As long as the weapon is in good running order you will be fine.

Malamute
April 5, 2011, 12:13 AM
The throats may be a bit different, but that can vary in sporting guns.

I've shot many hundreds of rounds of 7.62x51 ball through an older Ruger M-77. Been OK so far.

Years ago, Ruger stated that all their sporting arms in 223 were fine for shooting 5.56 rounds in. I'd guess they did the same (regarding throating) with the 308's, but have not heard specifically. Mine has been fine.

FMJMIKE
April 5, 2011, 06:15 AM
Thanks Guys !!!

FMJMIKE
April 5, 2011, 06:23 AM
Thanks Guys !!!

P-32
April 5, 2011, 07:30 AM
Been there and got the T-shirt with no problems.

TonyAngel
April 6, 2011, 10:56 PM
I tried out some 7.62X51 in my semi custom bolt gun this past weekend. On some rounds, I couldn't get the bolt closed, on others the bolt was a bit hard to close. I'm running a really tight chamber that was cut for SMKs though.

Mr_Pale_Horse
April 7, 2011, 05:33 PM
If it is non-corrosive, non AP, non incendiary, run of the mill ball, sure.

helotaxi
April 7, 2011, 06:46 PM
The issue is one of headspace tolerance with the looser spec going to the 7.62 NATO. If the bolt will close, pressure won't be an issue but as mentioned above, depending on source, the NATO ammo might have a long body that would be fine in a NATO chamber but simply won't chamber in a SAAMI spec .308Win rifle.

Going the other way can present some interesting problems. The .308 uses a higher max chamber pressure, but the real problem is with the brass. The NATO round uses thicker brass to keep from rupturing when fired in a loose chamber. Firing a .308 in the same loose chamber could result in a case head separation as the brass expands to fill the chamber and the thin brass forward of the web is stretched to failure. Fairly unpleasant situation especially in a semi-auto where the bolt could well unlock right about the same time.

TexasRifleman
April 7, 2011, 07:14 PM
the .308 uses a higher max chamber pressure

no it doesn't

The pressures are measured in different ways, one in copper units of pressure, the other psi.

The pressures are the same, the numbers just look different.

52000 CUP and 60000 psi are the same thing for all practical purposes.

http://www.shootingsoftware.com/ftp/psicuparticle2.pdf

The reason people always think 308 is higher pressure is because of the brass being thinner. In a loose chamber you see more ruptures with the thinner brass which LOOKS like higher pressure.

Robert
April 7, 2011, 07:17 PM
The .308 uses a higher max chamber pressure
Can you cite please? I believe TR is correct in that the chamber pressures are not that much different. At least not enough to cause a problem.

helotaxi
April 7, 2011, 10:16 PM
It's not much of a difference, I agree. 2-5k psi IIRC. I'll try to find the source. The chamber and brass are the major issue.

ETA: I remembered incorrectly. 7.62 NATO is specified by CIP as 50k PSI (CIP only uses PSI not copper crusher CUP). SAAMI specifies the .308 Win at 62k PSI max pressure.

http://www.surplusrifle.com/shooting2006/308vs762nato/index.asp

Carl N. Brown
April 7, 2011, 11:01 PM
I would warn about using .308 in a military rifle. .308 Winchester loaded for bolt action rifles may have brass thinner or softer than the brass some military rifles were designed to handle. I don't shoot commercial .308 in my son's FAL, military 7.62 NATO only. We have shot both in his Savage 110.

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