Gentlemen,
As a former rifle competition shooter, let's just simplify the details to ONE statement: DON'T SHOOT OVERSIZED BULLETS IN A STANDARD .308" barrel!!
The oversized bullets (.310, .311", etc), may not give you any immediate bad results, but in the long-term, they will ruin your .308" barrel for accurate shooting using .308" bullets.
This has been well-proven many times.
Match shooters used to use slightly over-sized (.309" diameter) bullets to extend the useful accuracy life of barrels that had a lot of round through them. Guess what? After firing a few dozen of the oversized bullets, going back to standard .308" bullets proved disastrous! All match accuracy completely GONE!
So, if you treasure that good barrel, do yourself a favor and DON'T shoot oversized bullets through it.
John