An ammunition magazine for a firearm uses a spacer to extend the grip. The spacer is attached to the magazine's tube using a combined fastener and detent mechanism which acts between the magazine's butt plate and floor plate. The butt plate is attached to the magazine tube and the spacer is captured between the butt plate and floor plate.

Embodiments of the invention include a firearm system and method of assembly of the firearm system including a receiver complex including a receiver coupled to a forward receiver. A feed port is positioned between the receiver and the forward receiver, and a striker coil assembly is positioned proximate the receiver, and includes a plurality of strikers each extending at least partially through a coil. An interchangeable barrel is coupled to the forward receiver forming a breech. In some embodiments, the firearm system includes a breech that includes a plurality of side-by-side bores of the barrel. Some embodiments include a magazine coupled to the receiver complex adjacent the feedport to simultaneously feed more than one dischargeable projectile into the feedport with a single charge block. In some embodiments, the charge block includes a plurality of chambers and a plurality of projectiles positioned within the plurality of chambers.

Embodiments of the invention include a firearm system and method of assembly of the firearm system including a receiver complex including a receiver coupled to a forward receiver. A feed port is positioned between the receiver and the forward receiver, and a striker coil assembly is positioned proximate the receiver, and includes a plurality of strikers each extending at least partially through a coil. An interchangeable barrel is coupled to the forward receiver forming a breech. In some embodiments, the firearm system includes a breech that includes a plurality of side-by-side bores of the barrel. Some embodiments include a magazine coupled to the receiver complex adjacent the feedport to simultaneously feed more than one dischargeable projectile into the feedport with a single charge block. In some embodiments, the charge block includes a plurality of chambers and a plurality of projectiles positioned within the plurality of chambers.

A firearm assembly includes an insert including a front strap, a leading member, a dowel member located at a lower end of the leading member, and a floorplate flexibly coupled to a lower end of the front strap, wherein the front strap and leading member extend between an upper end of the insert and a lower end of the insert; a follower configured to move vertically in relation to the insert; a rear strap removably attachable to the floorplate; and a spring disposed above the floorplate, wherein the front strap and rear strap are internally disposed in the spring and the follower is removably attached to an upper end of the spring.

A location-based gun magazine has a housing having a plurality of locking apertures, a spring, a wireless receiver switching device, a battery, and an electromagnet locking mechanism. The electromagnet locking mechanism has a locking tab for engaging and locking with the plurality of locking apertures, the locking tab actuatable via the electromagnet, the electromagnet receiving a signal from the wireless receiver switching device. The wireless receiver switching device may have a radio receiver, a GPS chip, or other device for receiving location-based information.

A practice magazine includes a housing that at least partially houses one or more weights, a rotating or pivoting follower, and a spring for biasing the follower in a first direction that is toward the slide of a firearm when the practice magazine is positioned in the magazine compartment of the firearm. The housing also includes a magazine catch notch and additional features to cooperate with the firearm magazine compartment's geometry. The follower attaches to the housing at a pivot support around which it can rotate, and the housing and follower include a stopper arrangement that limits excessive rotation of the follower. The spring, disposed between the follower and housing, produces tension when the practice magazine is fully inserted into the magazine compartment of the firearm. The weights are disposed in the housing to mimic the weight of loaded ammunition.

A practice magazine includes a housing that at least partially houses one or more weights, a rotating or pivoting follower, and a spring for biasing the follower in a first direction that is toward the slide of a firearm when the practice magazine is positioned in the magazine compartment of the firearm. The housing also includes a magazine catch notch and additional features to cooperate with the firearm magazine compartment's geometry. The follower attaches to the housing at a pivot support around which it can rotate, and the housing and follower include a stopper arrangement that limits excessive rotation of the follower. The spring, disposed between the follower and housing, produces tension when the practice magazine is fully inserted into the magazine compartment of the firearm. The weights are disposed in the housing to mimic the weight of loaded ammunition.

A magazine floor plate for a firearm magazine includes sidewalls that extend vertically from floor plate and define an interior cavity for accommodating a portion of the firearm magazine. The sidewalls include a first parallel longitudinal sidewall, a second parallel longitudinal sidewall, a first parallel traverse sidewall, and a second parallel traverse sidewall. The magazine floor plate further includes a locking mechanism for insertion between the firearm magazine and at least one of the sidewalls when the interior cavity accommodates the portion of the firearm magazine. The first and second parallel longitudinal sidewalls have a length greater than the firearm magazine.

A magazine floor plate for a firearm magazine includes sidewalls that extend vertically from floor plate and define an interior cavity for accommodating a portion of the firearm magazine. The sidewalls include a first parallel longitudinal sidewall, a second parallel longitudinal sidewall, a first parallel traverse sidewall, and a second parallel traverse sidewall. The magazine floor plate further includes a locking mechanism for insertion between the firearm magazine and at least one of the sidewalls when the interior cavity accommodates the portion of the firearm magazine. The first and second parallel longitudinal sidewalls have a length greater than the firearm magazine.

Apparatus, systems, and methods for an adjustable magazine lockup. A magazine body includes a slot in a first side with feed lips connected to the top side. The feed lips have a top edge positioned away from the top side of the magazine body. A first insert with a first lockup notch may be positioned within the slot so that there is a first distance from the top edge of the feed lips to a centerline of the first lockup notch. The insert may be replaced to change to the top edge of the feed lips. A second insert having a second lockup notch may be inserted into the slot in the first side of the magazine body to increase the distance and a third insert having a third lockup notch may be inserted into the slot in the first side of the magazine body to decrease the distance.