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.