I needed a little practice with the 308s, so I decided to shoot some of the 7.62x51 Calvim surplus ammo I had laying around. The M1A had no feeding or extraction issues. The extraction was a little tight from the Steyr, but nothing extreme.

I then shot a little commercial 308 in the Steyr. It didn�t have any issues with extraction.

So all is well except, I still need some more practice. So I reloaded the 308 and 7.62 brass. When I get to the range the 308 feeds fine for the Steyr, but the 7.62 rounds will not feed all the way into the chamber. The 7.62 rounds feed fine in the M1A.

What did I do wrong?
I know the chamber on the Steyr is tighter, but...?
I full length sized the brass.

I think you answered your own question, tighter chamber. Try sizing in a set of small base dies.

You know, I thought about that, but I sized the 7.62 and the 308 in the same dies.