The Mossberg 590M replaces the traditional tube magazine with a detachable box magazine, enabling faster reloads. It accepts proprietary 5, 10, and 20-round magazines and retains all other 590A1 heavy-duty specifications. Type: Shotgun Action: Pump-Action Caliber: 12 Gauge Capacity: 10 Year introduced: 2019, USA Weight: 7.5 oz Overall length: 39.5" Status: Active Intended use: Tactical