A buddy of mine has a new M-1A and he started using federal premium match ammo in it because the military stuff just shot like crap in it.  I mentioned to him about the powder burn rates and slower burning commercial stuff bending OP rods.  He said he never heard of such crazy talk, the M-1 is a perfect design and it can't fail. After all he did carry one in viet nam!

So does anyone have a definite answer if that ammo or any off the shelf match ammo that didn't come from cmp is safe for op rods?

Thanks

I don't believe the issue with M1As is related to powder differences, though that is true with 30-06 and the garands.  The bigger issue is 308 vs 762x51.  It's like 223vs556 but flipped; the 308 loads are significantly hotter than 7.62.  Can be very bad for the weapon

It's fine. Springfield's only recommendation on the matter is not to use "light magnum" loads, such as those so labelled from Hornady.

This is the potential problem, higher-pressured .308 commercial loads.  When I got my M1A back in the 1990s they recommended 7.62 only.

It's not as simple as ".223/5.56 flipped". It's a possible headspace issue combined with higher pressure and thinner case walls.





M1As have a vented gas cylinder to prevent op-rod damage, correct? I'd still follow Vortec's advice and not use "light magnum", Superformance or the like.





There was a thread in the Precision Rifle section comparing FGMM .308 and 7.62, though I can't remember what the difference was. Perhaps the MAP, and case annealing. I'm sure plenty of FGMM .308 has been put through M1As without issue.
 

I have a Springfield and the barrel is marked nm .308.

I assume that .308 ammo would be fine in this rifle.

What does your barrel say?

Not my rifle so not sure what it says, but it is a new springfield M-1A standard model.  Good to know about the vented gas cylinder.

About 10 or so years ago I was at the shot show and was talking to a remington rep at their ammo booth about their then new 308 match loads with 168 gr bullets and he told me that this stuff was developed for bolt action rifles and was not recommended for semi autos.

Just don't use any bullet weight higher than 175.