M1A question

[strat8]

Wondering if someone could let me know what the difference is between the 7.62 NATO and the 308 Winchester. I plan on purchasing an M1A soon and I see in the owners manual they specify 7.62 NATO ammo only. I plan on reloading for this rifle so is there a difference in reloading dies between the two? How about the brass? Can I shoot 308 Winchester ammo in this? Confused..

Thanks to all for any info.

 

[Double Vision]

To the best of my knowledge, .308 and 7.62 X 51 are basically the same.
They are often sold as interchangeable.

The M1A manual cautions against using anything other than 7.62 X 51 mostly because of the risk of slam fire from soft primers in anything other than NATO-spec ammo.

To date, I have only used Winchester 7.62 X 51 ammo in my M1A so I can't comment on results with the .308.

By all means, use care at all times but the risk may not be as high as the manual indicates.

 

[Flatbush Harry]

The Search function is your friend.

FH

 

[kmcintosh78]

Nothing really.
Any M1A will shoot both with no issues. Stay away from steel cased ammo.
I shoot Surplus out of mine with no issues.

 

[withdrawn34]

You should be able to shoot .308 in your 7.62 NATO M1A. I believe it's the other way around that can be problematic... but of course that case doesn't apply to your M1A.

 

[Candiru]

This may clarify things:

http://how-i-did-it.org/762vs308/

 

[LemmyCaution]

This note is specific to the M1a platform only:

.308win and 7.62x51 are interchangeable on the M1a platform, with the following caveat-

Keep the bullet weight below 180gr.

Heavier bullets, unless you have modified the gas system of the rifle to accommodate them, can bend the operating rod on the M1a. In extreme cases, the operating rod can hit the receiver hard enough to crack it.

The issue is not that the .308win commercial loads are loaded hotter, or that .308 is rated at a higher pressure than 7.62x51 (read elsewhere for a discussion of that issue). The issue is that the heavier bullets, though well within spec for chamber pressure create excess pressure at the gas port of the semi-automatic M1a. The excess pressure pushes the piston much harder with resultant effects further down the chain of the semi-automatic action.

It should also be noted that, when reloading for the M1a, one should keep to the range of powders specifically recommended for the M1a. A powder that burns too slowly may create a lower chamber pressure than a faster powder, but can create excess port pressure as a result of the slower combustion.