US12680771 - Caliber and feed-side convertible firearm
Disclosed herein is a firearm including a main body having attached thereto a trigger group, a belt feed mechanism, a bolt carrier group, a barrel extension group, a belt box mount, and a stock assembly. The trigger group engages a bottom face of the main body. The trigger group enables fully-automatic mode of operation or select-fire modes of operation (automatic and semi-automatic). The belt feed mechanism is user-selectively engaged with a left-side or a right-side engagement interface of the main body. A top portion (e.g., top surface) of the belt box mount may engage a mating interface at a bottom portion (e.g., bottom surface) of the main body for fixedly engaging the belt box mount to the main body in a manner that inhibits vertical separation of the belt box mount from the main body The stock assembly is engaged with a rear end portion of the main body.