[ARCHIVED THREAD] - M1A headspace question

Posted: 1/5/2011 8:04:12 AM EDT

I just bought a new SA M1A Loaded and haven't shot it yet. The shipping tag says the rifle headspaces at 1.631. I've got some American Eagle .308 Winchester ammo that I was going to try in it but I know that headspace spec for .308 is 1.634. I'm wondering if I'm going to have any problem using the .308.

Posted: 1/5/2011 8:58:50 AM EDT

[#1]

None at all unlesss you plan to reload.
Nominal headspace for commercial .308 headspace is 1.630"-1.633"
Nominal headpace for NATO 7.62X51 is 1.634"-1.638"
Either cartridge can be fired in either chamber dimension safely, the issue comes when attempting to reload the fired carrtridge cases as shoulder set back occurs when shooting 7.62X51 in a .308 dimension chamber and case stretch occurs when shooting commercial .308 in a 7.62X51 dimension chamber.
Either will lead to a very short case life when reloading.

If you plan to reload, stick with commercial .308 dimension cases for your rifle for best results.HTH

Posted: 1/5/2011 10:34:57 AM EDT

[#2]

I have the same headspace on my SA M1A standard and I haven't had any problem shooting any brand of commercial ammo. It also shoots surplus very well.

Is your AE ammo 150 or 168gr? Mine likes the 150, but loves the 168gr.

Posted: 1/5/2011 10:57:16 AM EDT

[#3]

Thanks, Milo. I do reload but pistol ammo only at present. I may buy some dies for the .308 eventually, so I appreciate your advice. I don't reload for my AR's because I've always thought they were a little too finicky about ammo.

Posted: 1/5/2011 10:58:04 AM EDT

[#4]

You are good to go. Mine headspaces at 1.631" as well. As stated earlier, minimum spec is 1.630. Be careful if you reload though.

Posted: 1/5/2011 10:59:02 AM EDT

[#5]

Thanks CTRob. The .308 I have on hand is 150 gr. Have you been getting any deals on mil surp?

Posted: 1/5/2011 11:03:03 AM EDT

[#6]

I shoot only milsurp cases in mine and when I size them I bump the shoulder back to 1.628" rifle is HS at 1.632" and have not had a single issue

[ARCHIVED THREAD] - M1A headspace question

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[ARCHIVED THREAD] - M1A headspace question

[ARCHIVED THREAD] - M1A headspace question