The Benelli M4 (M1014 (U.S. Marine Corps designation); Benelli M4 Super 90) is an Italian semi-automatic combat shotgun designed for CQB (Close Quarters Combat). It is a gas-operated shotgun, and was designed by Benelli in 1998.
The Benelli M4 was the first semi-automatic shotgun produced by Benelli, in response to a request for a 12 gauge, semi-automatic shotgun for use by the U.S. armed forces.
The Benelli M4 is mainly used by the United States Marine Corps, under the designation "M1014". It has also seen use by the British Military under the designation "L12A1" and comes equipped with a folding foregrip and EOTECH sight.
The Benelli M4 is a semi-automatic, gas-operated 12 gauge shotgun. It features a gas system that is self-regulating; that is, it will function with several different 12 gauge loads of varying power. Weaker loads (rubber pellets, bean bags, breaching loads) must be cycled manually.
The gas system is short-stroke piston; it uses two stainless-steel actuator rods that impinge against the rotating bolt when the weapon is fired, causing the bolt to unlock and cycle, extracting and ejecting the spent cartridge.