The Mossberg 590M Shockwave combines the non-NFA bird-head grip configuration of the Shockwave with the detachable magazine system of the 590M, providing 10-round magazine-fed capacity in an extremely compact non-NFA package. Type: Shotgun Action: Pump-Action Caliber: 12 Gauge Capacity: 10 Year introduced: 2020, USA Weight: 5.75 oz Overall length: 26.37" Status: Active Intended use: Tactical/Novelty