The Benelli M4 Super 90 is a gas-operated semi-automatic shotgun developed for the U.S. Marine Corps under the Joint Service Combat Shotgun program, featuring Benelli's ARGO (Auto-Regulating Gas-Operated) system. Type: Shotgun Action: Semi-Automatic Caliber: 12 Gauge Capacity: 5 Year introduced: 1998, Italy Weight: 64 oz Overall length: 40" Status: production Military use: Yes Intended use: military,law-enforcement,tactical