The Benelli M4 is a semi-automatic shotgun produced by Italian firearm manufacturer Benelli Armi SpA, and the fourth and last model of the Benelli Super 90 line of semi-automatic shotguns. The M4 uses a proprietary action design called the "auto-regulating gas-operated" (ARGO) system, which was created specifically for the weapon. Designed in 1998, the M4 was adopted by the armed forces of Italy, the United States, and United Kingdom, among others, and has been used in a variety of conflicts.
A U.S. Marine firing an M1014 shotgun as part of training in December 2006
U.S. Marines firing their M1014s and Mossberg 500s
Marine Corps diagram of a field-stripped M1014
A combat shotgun is a shotgun issued by militaries for warfare. The earliest shotguns specifically designed for combat were the trench guns or trench shotguns issued in World War I. While limited in range, the multiple projectiles typically used in a shotgun shell provide increased hit probability unmatched by other small arms.
Confederate cavalryman with muzzle-loading shotgun
A group of US Marines in Iraq in 2005, armed with a combat shotgun, assault rifle, and squad automatic weapon
United States Marine carrying a Winchester M97 shotgun
A Mossberg 590 being used by a US Marine for door breaching in Karma, Iraq, in 2005
