US Patent 9528784 Drum magazine assembly and methods

A drum magazine assembly and methods are described. A drum assembly has a follower assembly, a drum body, a spring assembly, and a feed tower assembly. The follower assembly biases cartridges towards an exit of the feed tower assembly. The follower assembly has a plurality of dummy cartridges, the plurality of dummy cartridges having a leading dummy cartridge and a last dummy cartridge, and a plurality of links including a leading link and a last link. The last dummy cartridge rotates relative to the last link and the leading link, and the leading dummy cartridge has a bolt catch engagement feature.