Mossberg 590A1, Pump Action Shotgun, 12 Gauge, 3 Chamber, 18.5 Barrel, Ghost Ring Sight, Black Synthetic Stock and Forend, Cerakote Finish, Tungsten Gray, 6 Rounds 50790 Selected by the U.S. armed forces after passing the rigors of MilSpec qualification, the 590A1 is the duty shotgun of choice for military and law enforcement agencies worldwide. 590A1 models offer a variety of sighting options to meet mission-specific needs.