The Mossberg 590A1 is the military-specification pump shotgun with 20-inch heavy-walled barrel, metal trigger guard, metal safety, and extended 8+1 magazine capacity. Passed all six US military shotgun specifications. Used by US military and law enforcement worldwide. Type: Pump Shotgun Action: Pump-Action Caliber: 12 Gauge Capacity: 8 Year introduced: 1987, USA Weight: 7.25 oz Overall length: 41" Status: Active Military use: Yes Intended use: Military, Law Enforcement, Tactical, Home Defense