Mossberg 590RM

About the Mossberg 590RM

The Mossberg 590RM is a magazine-fed pump-action 12-gauge shotgun introduced in 2026, building on the proven 590 platform with two headline upgrades: an AR-15-style rotary safety selector (the 'RM' designation) and a first-of-its-kind industrially produced double-stack detachable box magazine. The 2.75-inch-chambered shotgun feeds from polymer magazines available in 5, 10, and 15-round capacities, replacing the tubular magazine traditional to pump guns and allowing far faster reloads. It ships with an 18.5-inch stand-off barrel with an integrated heat shield, Magpul MBUS 3 flip-up sights, a top Picatinny rail, a five-position adjustable stock, and a Magpul MOE pistol grip. The ambidextrous rotary safety sits in the familiar AR-15 position, letting the shooter engage or disengage the safety without breaking firing grip - making it well suited to tactical, duty, and home-defense roles.

Pump shotguns have always traded firepower for reload speed - a 590 runs dry and the shooter must thumb shells in one at a time. The 590RM rewrites that equation with a double-stack box magazine, the first of its kind mass-produced, paired with an AR-pattern rotary safety so operators trained on carbines never have to relearn the manual of arms when they pick up the scattergun.

Mossberg 590RM specifications

The 590RM uses the same double-stack 590M-pattern detachable magazines (5/10/15/20-round); 10-round is the standard supplied magazine. The defining change versus the 590M is the AR-style rotary safety selector. Empty weight and overall length not confirmed at launch.