I love ringing steel at 300 yards, free hand, 5.56 and 4 moa Aimpoint Micro H-1, unmagnified.
400 hundred yards is more challenging free hand, but not really a problem on a rest.
Mind you I'm not going for groups, just making steel sing.
Assumption is the mother of all ****ups.
Know what you know, Know what you don't know. -Paul Pedzolt
"Jack of all trades, master of none, though oftentimes better than master of one" -Mynshul