Abstract: 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.

Abstract: A drum style magazine for a firearm is disclosed. The magazine has a tower and a magazine body. The magazine body contains a cartridge gear for holding and carrying cartridges of ammunition. The cartridge gear has two rows of teeth, separated by a channel. Cartridges can be held between the teeth of the rows. The gear has a unique shape that makes it relatively easy to manufacture.

Abstract: A cover for a firearm is disclosed. The firearm cover is shaped to complement the bottom of an upper portion of a two piece receiver. The firearm cover may be pinned to the bottom of an AR-15® upper receiver and may cover a bottom opening and/or a rear opening when in place. When secured in place, the firearm cover may capture a bolt carrier within an inner cavity of the upper receiver. Additionally, the firearm cover will protect the inner cavity, keeping dust, debris, and moisture out of the upper receiver.

Abstract: A modular magazine for a firearm is disclosed. The magazine has a tower and a magazine body. The tower and magazine body are modular and can be disconnected from each other. When disconnected, the tower can be paired with other magazine bodies. Also, the magazine body may be connected to other suitable towers. Different towers may allow a magazine to connect with a plurality of styles of firearm. Also, a plurality of styles of magazine may be used with a single firearm when connected to a suitable modular tower.

Abstract: A cover for a firearm is disclosed. The firearm cover is shaped to complement the bottom of an upper portion of a two piece receiver. The firearm cover may be pinned to the bottom of an AR-15® upper receiver and may cover a bottom opening and/or a rear opening with in place. When secured in place, the firearm cover may capture a bolt carrier within an inner cavity of the upper receiver. Additionally, the firearm cover will protect the inner cavity, keeping dust, debris, and moisture out of the upper receiver.

Abstract: A modular magazine for a firearm is disclosed. The magazine has a tower and a magazine body. The tower and magazine body are modular and can be disconnected from each other. When disconnected, the tower can be paired with other magazine bodies. Also, the magazine body may be connected to other suitable towers. Different towers may allow a magazine to connect with a plurality of styles of firearm. Also, a plurality of styles of magazine may be used with a single firearm when connected to a suitable modular tower.

Abstract: A drum style magazine for a firearm is disclosed. The magazine has a tower and a magazine body. The magazine body contains a cartridge gear for holding and carrying cartridges of ammunition. The cartridge gear has two rows of teeth, separated by a channel. Cartridges can be held between the teeth of the rows. The gear has a unique shape that makes it relatively easy to manufacture.