Abstract: A system and method for using a firearm magazine are described. One example includes a firearm magazine assembly. The assembly has a housing defining a cartridge track, the housing having a distal end having feed lips for feeding cartridges to a firearm and a proximal end. The assembly also has a follower assembly having a follower and a spring. The follower has a proximal side and a distal side and is movable between a compressed position and an extended position. The follower engages the housing in the extended position without biasing the feed lips away from each other, whereby the follower prevents creep of the distal end of the housing when the follower is in the extended position.

Abstract: A stock and related methods for a firearm are disclosed. An exemplary stock includes a distal portion for interfacing with a firearm, the distal portion having one of a lock catch or a lock and one of a detent or a detent notch distinct from the one of a lock catch or a lock. The exemplary stock further includes a proximal portion, the proximal portion having the other one of a lock catch or a lock and the other one of a detent or a detent notch. The exemplary stock has a folded configuration and an unfolded configuration. The exemplary lock is shaped to engage the lock catch to selectively maintain the stock in the unfolded configuration. The exemplary detent is shaped to engage the detent notch to selectively maintain the stock in the folded configuration.

Abstract: A drum magazine assembly and methods are described. A drum assembly has a follower assembly, a drum body, a spring assembly, and a feed tower assembly. The follower assembly biases cartridges towards an exit of the feed tower assembly. The follower assembly has a plurality of dummy cartridges, the plurality of dummy cartridges having a leading dummy cartridge and a last dummy cartridge, and a plurality of links including a leading link and a last link. The last dummy cartridge rotates relative to the last link and the leading link, and the leading dummy cartridge has a bolt catch engagement feature.

Abstract: An accessory mounting interface for a firearm is provided. The accessory mounting interface has a firearm accessory, a first elongated fastener, a second fastener, and an elongated slot in a firearm. The second fastener has two straight edges parallel to each other, and at least one of the two straight edges prevent the second fastener from rotating beyond a closed position once a portion of the second fastener has passed through and at least partially cleared the elongated slot.

Abstract: A quick detach mount and method are disclosed. The mount includes an accessory receiving portion shaped to receive a quick detach interface, and a first arm extending from the accessory receiving portion. The quick detach mount is shaped to receive a first fastener and a second fastener, whereby the quick detach mount is shaped distribute a force from the accessory receiving portion.

Abstract: A system and method for using a firearm magazine are described. One example includes a firearm magazine assembly. The assembly has a housing defining a cartridge track, the housing having a distal end having feed lips for feeding cartridges to a firearm and a proximal end. The assembly also has a follower assembly having a follower and a spring. The follower has aproximal side and a distal side and is movable between a compressed position and an extended position. The follower further has at least two angled surfaces to engage the housing and bias the feed lips towards each other when the follower is in the extended position.

Abstract: A follower for a firearm magazine is provided. In some embodiments, the follower has: a cartridge platform coupling a first wall to a second wall. The first wall, the second wall, and the platform define a receiving space for receiving at least a portion of a magazine spring. At least one of the first wall or the second wall has a nonlinear end profile shaped to translate a lateral spring force into a longitudinal spring force.

Abstract: A stock assembly and method are disclosed. The stock assembly may have a receiver extension assembly and a lower stock assembly removably and slidingly attached to the receiver extension assembly. The receiver extension assembly may have a receiver extension including an outer tube shaped to fit around the receiver extension, and an end plate. The end plate may be shaped to at least partially fit around the receiver extension and engage a distal end of the outer tube and a proximal end of a receiver to maintain the outer tube in alignment with the receiver. The lower stock assembly may have a lock box including at least one rail shaped to slidingly engage at least one rail in the outer tube, and at least one pawl biased towards selective engagement with one or more teeth in the outer tube.

Abstract: A stock assembly and method are disclosed. The stock assembly may have a receiver extension assembly and a lower stock assembly removably and slidingly attached to the receiver extension assembly. The receiver extension assembly may have a receiver extension including an outer tube shaped to fit around the receiver extension, and an end plate. The end plate may be shaped to at least partially fit around the receiver extension and engage a distal end of the outer tube and a proximal end of a receiver to maintain the outer tube in alignment with the receiver. The lower stock assembly may have a lock box including at least one rail shaped to slidingly engage at least one rail in the outer tube, and at least one pawl biased towards selective engagement with one or more teeth in the outer tube.

Abstract: A stock-to-firearm interface for mounting a stock to a firearm is disclosed. In one example, a stock-to-firearm interface for mounting a stock to a firearm is provided. The stock-to-firearm interface may have a proximal end, and a distal end shaped to interface with a recess in a firearm. The distal end may have a modifiable firearm mount shaped to at least partially fit within the recess, and may have an adjustable maximum profile. The stock-to-firearm interface may mount one of a folding stock and a fixed stock to a firearm.

Abstract: A follower for a firearm magazine is disclosed, with a platform that may support a cartridge and has a top surface defining a plane and a bottom surface. The front end may be coupled to a front portion of the platform and engage a spring and a magazine body. The interior surface of the front end may be substantially perpendicular to the bottom surface of the platform and form an obtuse angle with the plane of the platform. The rear end may be coupled to a rear portion of the platform and engage the spring and the magazine body. The interior surface of the rear end may be perpendicular to the bottom surface of the platform and form an acute angle with the plane of the platform. The front end may extend further below the platform than does the rear end.

Abstract: A system and method for using a firearm magazine are described. One example includes a firearm magazine assembly. The assembly has a housing defining a cartridge track, the housing having a distal end having feed lips for feeding cartridges to a firearm and a proximal end. The assembly also has a follower assembly having a follower and a spring. The follower has aproximal side and a distal side and is movable between a compressed position and an extended position. The follower further has at least two angled surfaces to engage the housing and bias the feed lips towards each other when the follower is in the extended position.

Abstract: A follower for a firearm magazine is provided. In some embodiments, the follower has: a platform shaped to interface with a firearm cartridge; a first side face extending longitudinally from the platform and having a first end opposing the platform; and a second side face extending longitudinally from the platform and having a second end opposing the platform. The first side face and the second side face may define a receiving space for receiving at least a portion of a magazine spring. At least one of the first end and the second end may have a nonlinear profile shaped to translate a lateral spring force into a longitudinal spring force.

Abstract: An accessory mounting interface for a firearm is provided. The accessory mounting interface has a firearm accessory, a first elongated fastener, a second fastener, and an elongated slot in a firearm. The second fastener has two straight edges parallel to each other, and at least one of the two straight edges prevent the second fastener from rotating beyond a closed position once a portion of the second fastener has passed through and at least partially cleared the elongated slot.

Abstract: A follower for a firearm magazine is provided. In some embodiments, the follower has: a platform shaped to interface with a firearm cartridge; a first side face extending longitudinally from the platform and having a first end opposing the platform; and a second side face extending longitudinally from the platform and having a second end opposing the platform. The first side face and the second side face may define a receiving space for receiving at least a portion of a magazine spring. At least one of the first end and the second end may have a nonlinear profile shaped to translate a lateral spring force into a longitudinal spring force.

Abstract: The present disclosure provides a method of creating a visible indicator upon a firearm magazine. The method may comprise fabricating a plurality of rectangular matrices of divots on an exterior surface of the magazine, the divots having concave surfaces, each matrix comprising a plurality of rows of divots and a plurality of columns of divots. A first divot of a first row is also a first divot of a first column, the first divot forming a substantially straight line with each other divot of the first column, and a first divot of a second row is also a second divot of the first column. The method may then comprise marking, with paint or ink, at least one of the divots.

Abstract: A system and method for using a firearm magazine are described. One embodiment includes a firearm magazine assembly. The assembly has a polymer housing and a follower assembly comprising a follower, a spring, and an insert. The assembly also has a floorplate removably engaged with the proximal end of the housing and the insert. The follower assembly comprises a compressed configuration and an extended configuration relative to the housing, a compression limiter, and an extension limiter. The compression limiter prevents the spring from over-compression, and the extension limiter prevents the spring from forcing the follower against the feed lips.

Abstract: An accessory mounting interface for a firearm is provided. The accessory mounting interface has a firearm accessory, a first elongated fastener, a second fastener, and an elongated slot in a firearm. The second fastener has two straight edges parallel to each other, and at least one of the two straight edges prevent the second fastener from rotating beyond a closed position once a portion of the second fastener has passed through and at least partially cleared the elongated slot.

Abstract: A stock-to-firearm interface for mounting a stock to a firearm is disclosed. In one example, a stock-to-firearm interface for mounting a stock to a firearm is provided. The stock-to-firearm interface may have a proximal end, and a distal end shaped to interface with a recess in a firearm. The distal end may have a modifiable firearm mount shaped to at least partially fit within the recess, and may have an adjustable maximum profile. The stock-to-firearm interface may mount one of a folding stock and a fixed stock to a firearm.

Abstract: A system and method for a user's appendages when firing a weapon is described. One embodiment includes a cover kit for a firearm handguard. The kit has a base and an insert. The base has a longitudinal axis, an upright axis, a transverse axis, a socket, an exterior surface, and an interior surface. The insert has an insert body and a plug. The socket has a movable engagement prong shaped to engage a wall surface of a handguard slot. The plug has a prong engagement surface shaped to engage the engagement prong. The plug is shaped to apply a force on the engagement prong such that a distal portion of the engagement prong is flexed more than a proximal portion of the engagement prong.