Abstract: A device may include an elongated body comprising an opening configured to receive a receiver extension tube of a firearm. A device may include a brace body affixed distally to the elongated body and comprising a window configured to receive a clamp mount, wherein the clamp mount is configured to retain the arm brace in a fixed position on the receiver extension tube and comprises: one or more clamps comprising at least one through-hole and one or more pads, wherein the one or more pads are configured to engage with the receiver extension tube via adjustment of one or more fasteners interfacing with the at least one though-hole.

Abstract: An accessory mounting interface for a firearm, and a related method, are disclosed. The interface has a firearm accessory, a first elongated fastener, and a second fastener rotationally mated to the first elongated fastener. The first elongated fastener has right-handed threading and is arranged through a through hole in the firearm accessory with a first end extending below first and second halves of a first slot protrusion of the firearm accessory. The second fastener has a length greater than a width, the length measured along a longitudinal axis of the second fastener, the second fastener having a plurality of straight edges. At least one of the plurality of straight edges prevents the second fastener from rotating further than a closed position when the at least one of the straight edges abuts a sidewall of an elongated slot in the firearm.

Abstract: An accessory mounting interface for a firearm, and a related method, are disclosed. The interface has a firearm accessory, a first elongated fastener, and a second fastener rotationally mated to the first elongated fastener. The first elongated fastener has right-handed threading and is arranged through a through hole in the firearm accessory with a first end extending below first and second halves of a first slot protrusion of the firearm accessory. The second fastener has a length greater than a width, the length measured along a longitudinal axis of the second fastener, the second fastener having a plurality of straight edges. At least one of the plurality of straight edges prevents the second fastener from rotating further than a closed position when the at least one of the straight edges abuts a sidewall of an elongated slot in the firearm.

Abstract: This disclosure describes a firearm stock or arm brace with an adjustable length of pull. The stock or arm brace can include a body and lower stock, where the body includes a buffer tube receiving aperture and the lower stock includes a hollow cavity with a plunger and two concentric springs therein. One or more buttons can be affixed to sides of the plunger in the hollow cavity that can be used to depress the plunger against the force of one or both of the springs. One of the two springs may be shorter than the other and have a greater spring constant than the longer spring. Depressing the plunger against the taller spring may allow a user to adjust the length of pull while greater pressure and engagement of the second spring allows the stock or arm brace to be removed from a buffer tube or receiver extension.

Abstract: An accessory mounting interface for a firearm, and a related method, are disclosed. The interface has a firearm accessory, a first elongated fastener, and a second fastener rotationally mated to the first elongated fastener. The first elongated fastener has right-handed threading and is arranged through a through hole in the firearm accessory with a first end extending below first and second halves of a first slot protrusion of the firearm accessory. The second fastener has a length greater than a width, the length measured along a longitudinal axis of the second fastener, the second fastener having a plurality of straight edges. At least one of the plurality of straight edges prevents the second fastener from rotating further than a closed position when the at least one of the straight edges abuts a sidewall of an elongated slot in the firearm.

Abstract: This disclosure describes a firearm stock or arm brace with an adjustable length of pull. The stock or arm brace can include a body and lower stock, where the body includes a buffer tube receiving aperture and the lower stock includes a hollow cavity with a plunger and two concentric springs therein. One or more buttons can be affixed to sides of the plunger in the hollow cavity that can be used to depress the plunger against the force of one or both of the springs. One of the two springs may be shorter than the other and have a greater spring constant than the longer spring. Depressing the plunger against the taller spring may allow a user to adjust the length of pull while greater pressure and engagement of the second spring allows the stock or arm brace to be removed from a buffer tube or receiver extension.

Abstract: An accessory mounting interface for a firearm, and a related method, are disclosed. The interface has a firearm accessory, a first elongated fastener, and a second fastener rotationally mated to the first elongated fastener. The first elongated fastener has right-handed threading and is arranged through a through hole in the firearm accessory with a first end extending below first and second halves of a first slot protrusion of the firearm accessory. The second fastener has a length greater than a width, the length measured along a longitudinal axis of the second fastener, the second fastener having a plurality of straight edges. At least one of the plurality of straight edges prevents the second fastener from rotating further than a closed position when the at least one of the straight edges abuts a sidewall of an elongated slot in the firearm.

Abstract: A lock system and related methods are disclosed. The lock mechanism has a lock plate configured to be positioned adjacent the distal side of a firearm floor plate. The lock plate has a base plate and a disengagement mechanism affixed to a proximal side of the base plate. The disengagement mechanism has a protrusion configured to extend into the passage of the floor plate when the floor plate and the lock plate abut one another. The protrusion has a first portion and a second portion. The first portion is shaped to extend into the passage of the floor plate. The second portion is shaped to extend through the passage of the floor plate and protrude from the proximal side of the floor plate.

Abstract: An accessory mounting interface for a firearm, and a related method, are disclosed. The interface has a firearm accessory, a first elongated fastener, and a second fastener rotationally mated to the first elongated fastener. The first elongated fastener has right-handed threading and is arranged through a through hole in the firearm accessory with a first end extending below first and second halves of a first slot protrusion of the firearm accessory. The second fastener has a length greater than a width, the length measured along a longitudinal axis of the second fastener, the second fastener having a plurality of straight edges. At least one of the plurality of straight edges prevents the second fastener from rotating further than a closed position when the at least one of the straight edges abuts a sidewall of an elongated slot in the firearm.

Abstract: An accessory mounting interface for a firearm, and a related method, are disclosed. The interface has a firearm accessory, a first elongated fastener, and a second fastener rotationally mated to the first elongated fastener. The first elongated fastener has right-handed threading and is arranged through a through hole in the firearm accessory with a first end extending below first and second halves of a first slot protrusion of the firearm accessory. The second fastener has a length greater than a width, the length measured along a longitudinal axis of the second fastener, the second fastener having a plurality of straight edges. At least one of the plurality of straight edges prevents the second fastener from rotating further than a closed position when the at least one of the straight edges abuts a sidewall of an elongated slot in the firearm.

Abstract: A lock system and related methods are disclosed. The lock mechanism has a lock plate configured to be positioned adjacent the distal side of a firearm floor plate. The lock plate has a base plate and a disengagement mechanism affixed to a proximal side of the base plate. The disengagement mechanism has a protrusion configured to extend into the passage of the floor plate when the floor plate and the lock plate abut one another. The protrusion has a first portion and a second portion. The first portion is shaped to extend into the passage of the floor plate. The second portion is shaped to extend through the passage of the floor plate and protrude from the proximal side of the floor plate.

Abstract: An accessory mounting interface and method are disclosed. The interface has an upper portion having a firearm accessory and at least one through hole extending from a first surface to a second surface of the upper portion, the upper portion having a first post portion with a first side surface and a first flange. A first elongated fastener is arranged through the through hole and has a first end extending below the second surface of the upper portion. The interface also has a second post portion that is movable between a first configuration defining a first transverse distance between the first and second side surfaces and a second configuration defining a second transverse distance between the first and second side surfaces, the first transverse distance greater than the second transverse distance. The first flange substantially opposes the second flange when the second post portion is in the first configuration.

Abstract: A lock system and related methods are disclosed. The lock mechanism has a lock plate configured to be positioned adjacent the distal side of a firearm floor plate. The lock plate has a base plate and a disengagement mechanism affixed to a proximal side of the base plate. The disengagement mechanism has a protrusion configured to extend into the passage of the floor plate when the floor plate and the lock plate abut one another. The protrusion has a first portion and a second portion. The first portion is shaped to extend into the passage of the floor plate. The second portion is shaped to extend through the passage of the floor plate and protrude from the proximal side of the floor plate.

Abstract: A lock system and related methods are disclosed. The lock mechanism has a lock plate configured to be positioned adjacent the distal side of a firearm floor plate. The lock plate has a base plate and a disengagement mechanism affixed to a proximal side of the base plate. The disengagement mechanism has a protrusion configured to extend into the passage of the floor plate when the floor plate and the lock plate abut one another. The protrusion has a first portion and a second portion. The first portion is shaped to extend into the passage of the floor plate. The second portion is shaped to extend through the passage of the floor plate and protrude from the proximal side of the floor plate.

Abstract: An accessory mounting interface for a firearm, and a related method, are disclosed. The interface has a firearm accessory, a first elongated fastener, and a second fastener rotationally mated to the first elongated fastener. The first elongated fastener has right-handed threading and is arranged through a through hole in the firearm accessory with a first end extending below first and second halves of a first slot protrusion of the firearm accessory. The second fastener has a length greater than a width, the length measured along a longitudinal axis of the second fastener, the second fastener having a plurality of straight edges. At least one of the plurality of straight edges prevents the second fastener from rotating further than a closed position when the at least one of the straight edges abuts a sidewall of an elongated slot in the firearm.

Abstract: An accessory mounting interface and method are disclosed. The interface has an upper portion having a firearm accessory and at least one through hole extending from a first surface to a second surface of the upper portion, the upper portion having a first post portion with a first side surface and a first flange. A first elongated fastener is arranged through the through hole and has a first end extending below the second surface of the upper portion. The interface also has a second post portion that is movable between a first configuration defining a first transverse distance between the first and second side surfaces and a second configuration defining a second transverse distance between the first and second side surfaces, the first transverse distance greater than the second transverse distance. The first flange substantially opposes the second flange when the second post portion is in the first configuration.

Abstract: An accessory mounting interface for a firearm, and a related method, are disclosed. The interface has a firearm accessory, a first elongated fastener, and a second fastener rotationally mated to the first elongated fastener. The first elongated fastener has right-handed threading and is arranged through a through hole in the firearm accessory with a first end extending below first and second halves of a first slot protrusion of the firearm accessory. The second fastener has a length greater than a width, the length measured along a longitudinal axis of the second fastener, the second fastener having a plurality of straight edges. At least one of the plurality of straight edges prevents the second fastener from rotating further than a closed position when the at least one of the straight edges abuts a sidewall of an elongated slot in the firearm.

Abstract: An accessory mounting interface and method are disclosed. The interface has an upper portion having a firearm accessory and at least one through hole extending from a first surface to a second surface of the upper portion, the upper portion having a first post portion with a first side surface and a first flange. A first elongated fastener is arranged through the through hole and has a first end extending below the second surface of the upper portion. The interface also has a second post portion that is movable between a first configuration defining a first transverse distance between the first and second side surfaces and a second configuration defining a second transverse distance between the first and second side surfaces, the first transverse distance greater than the second transverse distance. The first flange substantially opposes the second flange when the second post portion is in the first configuration.

Abstract: A gunsmithing block is disclosed. The gunsmithing block has a first end for interfacing with a vice, and a second end shaped to interface with an upper receiver assembly of a firearm, the upper receiver assembly having an upper receiver, a bolt carrier without a bolt, and a barrel extension. The second end has an upper receiver mating portion shaped to interface with an interior region of the upper receiver and an interior region of the barrel extension. Methods of using and making a gunsmithing block are also disclosed.

Abstract: This disclosure describes systems, methods, and apparatus for a barrel support for a for a firearm stock. In one example, the barrel support has an elongate frame with a longitudinal axis extending between a fore portion and an aft portion, a first concave barrel recess shaped to support a first barrel, the first concave barrel recess positioned on a first side of the elongate frame. The exemplary barrel support also has a second concave barrel recess shaped to support a second barrel, the second concave barrel recess positioned on a second side of the elongate frame. In this example the first barrel is a tapered barrel, and the second barrel is a straight barrel.