Double Stack Box Magazine for Rimmed Cartridges of Varying Length

A double stack box magazine for rimmed ammunition cartridges of varied lengths, comprising:

• an elongated housing a neck portion in which cartridges are arranged in a single column and having a mouth at an upper feed end through which cartridges are inserted and extracted, a double-stack portion in which cartridges are arranged in laterally alternating columns, and a transition portion between the neck portion and the double-stack portion in which the two alternating columns are transitioned into the single column as the cartridges are moved toward the mouth within the housing;
• a follower configured to move along elongated guides in the housing;
• a spring configured to bias the follower toward the mouth;
• and
• a pair of rim clearance channels, one on each of opposed interior lateral surfaces of the housing, the channels having a first channel portion in which a width of the channels allows clearance for cartridge rims without respect to forward and rearward position of the cartridges within the housing which may vary depending on individual cartridge length, a second channel portion in the neck portion of the housing in which a forward edge of the channel provides an abutment against which laterally opposed areas of a cartridge rim bear to shift the cartridge to a rearward position within the housing as cartridges are moved toward the mouth, and a third channel portion providing transition between the first and second channel portions and configured to have a rearwardly sloped forward edge which confronts laterally opposed areas of a cartridge rim as cartridges are moved upwardly within the housing to the neck portion.