put up a couple of Pepper Poppers, 25m away, set to require a 230 gr .45 ball hit in order to knock them down. Get an electronic shooting timer from Dillon Precision, $150. From low ready (gunbutt between ribs and upper arm, safety engaged, finger outside of the guard, muzzle about 45 degrees downward. React to the timer's beep, raise the shotgun, down both poppers in 1.3 seconds. This is not at all hard to do with a flatttoped 223 Carbine and electronic sight. The popper has a 10" 'chest, is made of 3/8" steel plate, tapes downward about 18", from an 8" wide top to about a 4" wide bottom. It pivots on a pin, and has an adjustment screw, that determines which way it leans. You can lean it towards the shooter, for a .45 hit, or lean it back away from the shooter a bit, so that a 9mm will down it reliably.