My AR is a Colt Sporter (20" I believe). It's as stock as a stove, not counting a Trijicon ACOG and a decent trigger. I shoot factory ammo of all kinds, having never taken the time to see what it might like best. It routinely produces 1/2-3/4 " groups at 100 yards--just so long as I shoot slow enough to avoid heating up the barrel. The group size increases DRAMATICALLY with heat----might as well be throwing rocks.

Ralph Tremaine