Comment: Yes there are slight

(See in situ)

In reply to comment: Same gun same round? (see in situ)

Yes there are slight

Yes there are slight differences between 7.62x51mm NATO and .308 Winchester. That article is a good one also the wiki has some good info: http://en.wikipedia.org/wiki/.308 Generally however, interchanging the two is considered perfectly safe, The difference is something you should be aware of and as always read your owners manual or check with the rifle manufacturer just to be sure.

M1A is a brand name for Springfield Armory's semi-auto version of the M14.