2 gauge? modded grenade launchers perhaps. but those buckshots / slugs aren't any better than a 12 gauge. you see, a human simply cant handle the kick if you pack a 2 gauge with real power. it'd dislocate your shoulder and break your colarbone. and where did you fail to realise that shotgun slugs are fired from shotguns? i.e. 12 gauge slugs (or sabots) go into 12 gauge shotguns (without choke)?