Patent ID: 7441491

Claim:
A detachable magazine for storing and delivering ammunition to a firearm having a magazine well, the magazine comprising: a body having a column adapted for insertion into the magazine well; the column defining a passage for transmitting ammunition to the firearm; the column having a width selected to receive a double stack of ammunition; the body including a drum housing defining a substantially cylindrical chamber communicating with the column passage; a first sprocket element rotatably received in the chamber and having a serrated periphery with each serration adapted to receive an ammunition cartridge; a second sprocket element rotatably received in the chamber, and concentric with the first sprocket element, and having a serrated periphery with each serration adapted to receive an ammunition cartridge; a spring element operably connected to at least one of the sprocket elements, and operable to rotatably bias the sprocket elements to transmit cartridges from the drum chamber to the column passage; and wherein the serrations define centerlines that converge to a common point to the rear of the magazine, such that stored cartridges are arranged with their forward tips splayed outward from an axis defined by the sprocket elements.