If shot size is irrelevant to "stopping power", as has been implied by some posts, why do different shot sizes even exist? Heck, 7 1/2 is good enough for Canada Geese and bad guys with a .357.
Most (maybe all) shot sizes will produce a horrible, but shallow, surface wound on an attacker at 6 feet or 6 yards or whatever - but that is not the objective. THE objective is to
STOP the attacker and that may require much greater penetration. As noted previously in this thread, No. 1 buck has been shown to be the best and 00 is (a close) second place. FWIW, I still have several five shell boxes of Peters 2 3/4" Magnum Buckshot, 20 pellets, No. 1 Buck (price tag - $1.59), as well as much more recent production Federal 00 buck.
