Most hunters zero in their rifles at 100 yards. But, says McKee, with a .308 rifle firing a Federal Match round with a 168 grain bullet, for example, and zeroed at 100 yards, you will have to hold over about 16 inches on your big buck standing 300 yards away--probably way over his back. With a 200 yard zero, same scenario, your hold over is only nine to ten inches. Easier shot, as you (probably) aren't holding over your crosshairs into thin air! Note, though: with a 200 yards zero, same .308 round, your bullet will impact about two inches high at 100 yards.