You're right, obviously, the .308 FMJ stuff is more readily available, since the '06 is no longer a U.S. government issued round, and hasn't been for quite some time. I didn't realize that was what you were talking about, since I didn't even contemplate that those 500 round lots of ammo, manufactured all over the world, were the kind of stuff the original poster would want to use for long-range match ammo.

As far as the "national shooting competition data to prove the point"... I'm curious. Did they compare firearms that were identical except for cartridge? i.e. Rem 700 .308 vs. Rem 700 .30-06? Or are they saying that the .308 is now beating the .30-06 so the .308 must be more accurate.... but ignoring the differences between the M1 Garand and the M1A/M14?