Mossberg 590RM Mag-Fed 12 Gauge 18.5″ Pump

The Mossberg 590RM is a 12 gauge pump-action platform configured for magazine feeding and short-barrel stand-off use. It features an 18.5-inch stand-off barrel with an integrated heat shield, a 5-position adjustable stock paired with a Magpul MOE pistol grip, and a top Picatinny rail for optics and accessories. Built on an aircraft-grade aluminum receiver with a parkerized finish, the 590RM is designed for security and tactical applications where compact handling and modularity matter.

Key Specifications

• The gauge is 12 Gauge.
• The action is Pump-Action.
• The barrel measures 18.5 inches and uses a stand-off design with an integrated heat shield.
• The chamber accepts 2.75″ shells.
• The stock is a 5-position adjustable unit with a Magpul MOE pistol grip and interchangeable pad.
• Sights and mounting are provided via a top Picatinny rail.
• The receiver is aircraft-grade aluminum.
• The finish is parkerized.
• Length of pull is 12″–15.25″ (adjustable).
• The barrel uses an Accu-Choke system with a cylinder-bore choke indicated as included.

The 590RM blends Mossberg’s proven pump-action reliability with a magazine-fed configuration and compact stand-off barrel to deliver a versatile, modular platform for security-minded users. Its adjustable ergonomics, corrosion-resistant finish, and options for optics and accessory mounting make it a sensible choice for those who prioritize durable, adaptable equipment with straightforward serviceability.