The Benelli M4 is a gas-operated semi-automatic shotgun adopted by the United States Marine Corps as the M1014 Joint Service Combat Shotgun. Unlike other Benelli designs it uses a dual-piston ARGO gas system rather than inertia drive, chosen for its reliability with a wider range of ammunition and suppressors. Type: Shotgun Action: Semi-Automatic Caliber: 12 Gauge Capacity: 5 Year introduced: 1998, Italy Weight: 7.8 oz Overall length: 40" Status: Active Military use: Yes Intended use: Military, Law Enforcement, Home Defense