Mossberg 590, Pump Action, 20 Gauge, 3 Chamber, 18.5 Cylinder Barrel, Matte Blued Finish, Synthetic Stock, 6Rd, Bead Sight 50698 590 Tactical Shotguns. With credentials hard-earned over decades of military and law enforcement use, the 590 shotgun is the perfect choice for your personal and home defense needs. Features include Dual extractors, positive steel-to-steel lockup, twin action bars, and an anti-jam elevator ensure smooth operation. Top mounted safety provides for ambidextrous operation. Additional special features include tri-railed forends to facilitate accessory lights and lasers, adjustable stocks for rapid adjustment of length of pull.