Originally Posted by Hunter Welch
1000 yards is not an easy task with a .308 assuming this is a 1:12. It is do able though.
For what it's worth, Mike Walker (Remington engineer who developed the 7.62 NATO round, benchrest Hall of Fame) knew a 1:12 twist was best for the 147 - 150-gr. FMJBT bullet when fired from 22 inch service rifle barrels to get best accuracy all the way down range.
The USN and USAF M1 Garands rebarreled to 7.62 NATO for competition shot bullet weights from 150 up through 190 grains with excellent accuracy even at 1000 yards. Same for USA and USMC M14NM's but with bullets up to 180 grains. Tests proved commercial match ammo shot in the best of them would stay under 4 inches at 600 yards. Those Springfield Armory arsenal tight-bore match-spec'd barrels from Massachutches had 1:12 twists.
And Palma rifles have to use the .308 Win. round and bullets in the145 - 155 grain range typically use 1:13 twists. The best of them will stay under 7 inches at 1000 yards.
There's nothing wrong with a 1:12 twist in a .308 Win. barrel. Except it probably won't shoot boattails 200 grains or heavier really accurate. But round nose 200 grain hunting bullets do very well indeed.