Good articles on .308 ammo:
The Rifleman's Journal: Cartridges: 7.62 NATO Long Range Match Cartridges - Part 1
Some of the USA military rifle teams handloaded new Federal cases with 210M primers with about 44 grains of IMR4064 under Sierra 168's. They won a lot of matches and set some records with that load. It easily shot under 2/3 MOA at 600 yards in semiauto M14NM's. Federal GMM ammo with IMR4064 was equally as accurate. But only with new cases. Reloaded fired cases from M14's never shot as accurate regardless of how they were resized.
I've shot that same load in 7.62 NATO Garands as well as bolt action match rifles. It is indeed very accurate.
Federal loaded both IMR3031 and IMR4064 in that ammo and may have used a REloader powder, too. Best accuracy seemed to be with IMR4064 as IMR3031 dirtied up the barrels a lot more.