 Many Benelli shotguns utilize a inertia operating system developed by Bruno Civolani.In 1999 Benelli introduced the Benelli M4 Super 90, a gas operated semi-automatic shotgun intended for military and law enforcement use.The Benelli Super Black Eagle, used by waterfowlers, was one of the first semi-automatic shotguns capable of firing the 2.75, 3, and 3.5 inch shotgun shells.