US Patent 8225541 Magazine for a firearm

A magazine for a firearm is provided. The magazine includes a magazine box, a base removably coupled to the magazine box and a follower disposed in the magazine box. A spring is coupled to said follower to bias ammunition cartridges towards a firearm receiver. The base includes at least one opening sized to receive an arm on said follower when the magazine is loaded with ammunition cartridges. The distance between the bottom of the follower and top of the base may be arranged to be less than the diameter of an ammunition cartridge when the magazine contains a predetermined number of rounds.