Uncommon in other automatic shotguns, the AA-12 fires from an open bolt, a feature more commonly found in submachine guns, as well as heavy and squad-level machine guns. It uses 8-round box or 20-round drum magazines, as opposed to the original 5-round box magazine.
The AA-12's firing mechanism, which uses an open bolt, is uncommon for automatic shotguns but more common in submachine guns and heavy/squad-level machine guns. It utilizes 8-round box or 20-round drum magazines, unlike the original 5-round box magazine.