SRM Arms builds the M1216 in Meridian, Idaho. It is a 12-gauge semi-automatic that holds 16 rounds in four magazine tubes inside a cylindrical glass-filled polymer fore-end, which the shooter rotates by hand to bring each four-round tube into line to feed. Loading different shells in different tubes lets the shooter switch load types without unloading, or fire all 16 in sequence. The action is roller-delayed, which speeds cycling and reduces felt recoil, and the magazine assembly detaches from under the 18.5-inch barrel. The catalog lists Gen 2 guns with billet aluminium receivers and a Picatinny rail.