I shot some 3-gun with my Carbine, and it was great out to about 150 yards (much better than a .45, that's for sure), but when the distances got out beyond that, the trajectory, or, rather, taking the trajectory into account, made it hard to hit anything.
I think the bullet drops almost four feet at 350 yards.
I whiffed on sixteen, 12" targets at 300-400 yards, but I don't know how well you (I . . .) could do with anything at that distance, on a "two way range"?
S.L.A. Marshall did an extensive study of combat, and determined that individual targets were rarely engaged beyond 300 yards, since you generally can't see someone, who's trying to not be seen, at distances greater than that.
Didn't stop the U.S. from adopting the M14, or changing the ammo and barrels on the M16 for engaging out to 400 or more yards.