The Mossberg 590S optic-ready 12 gauge is a pump-action shotgun that cycles 1.75-inch, 2.75-inch and 3-inch shells interchangeably (brand part no. 51605). The receiver is cut for the Shield RMSc footprint, so a compact red dot mounts straight to the gun, and a bead front sight remains as a backup. The 18.5-inch barrel is finished in matte blue with a cylinder bore choke, and the stock is black synthetic. Mossberg adds a redesigned elevator and bolt slide, a new energy-absorbing bumper, dual extractors, twin action bars and steel-to-steel lockup for dependable cycling. This Mossberg suits home defense, security use and range work.

Key Specifications

• The gauge is 12 gauge with a 3-inch chamber, the standard full-length shell for the platform.
• The gun cycles 1.75-inch, 2.75-inch and 3-inch shells interchangeably, with no need for a mini-shell adapter.
• The action is pump action, with dual extractors, twin action bars and an anti-jam elevator.
• The barrel is 18.5 inches, a common length for security and home-defense shotguns.
• The barrel finish is matte blue, which keeps glare down.
• The choke is cylinder bore, a good all-around choice for buckshot and slugs.
• Mossberg lists capacity as 5+1, 6+1 and 9+1 for this model.
• The receiver is optic-ready for the Shield RMSc footprint, so a compatible red dot mounts without an extra base.
• The sight is a bead front sight, a simple fixed sight that remains usable with or without an optic.
• The stock is black synthetic with a 13.87-inch length of pull, which resists weather and handling wear.

Frequently Asked Questions

Which shell lengths does the 590S cycle? It cycles 1.75-inch, 2.75-inch and 3-inch shells interchangeably, and you can load any combination of those lengths at the same time.

Is the 590S Optic-Ready model cut for a red dot? Yes. The receiver is optic-ready for the Shield RMSc footprint.

How long and how heavy is it? Overall length is 39.5 inches and the shotgun weighs 6.75 pounds.

Buy the Mossberg 590S Optic-Ready 12 Gauge Pump Shotgun

The 590S Optic-Ready takes the proven Mossberg pump design and cuts the receiver for a compact red dot, with a bead sight still in place. Matte blue metal and a black synthetic stock keep it practical and rugged. Order it from our Lubbock, Texas gun shop for fast, insured shipping to your FFL, and check out more pump action shotguns as well.