Double column magazine

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A double column 9x19mm pistol magazine.

A double column magazine (sometimes also referred to as "double stack") is a magazine in which cartridges are stored in two side by side stacks, offset by one half cartridge height and resting against one another.

Older firearms used the simpler single column magazine where only a single stack or column of cartridges is stored in the magazine box.

Double column magazines roughly double the number of rounds which can be stored in the same vertical height of magazine space. They also roughly double the width of the magazine. For semi-automatic pistols, this means that the handgrip with the magazine inside it is significantly wider as well. These larger handgrips are a factor in user comfort, and ability to safely hold and properly operate larger double column magazine handguns.

There are two types double column magazines. The first has the feed terminated in the same double stack, with the cartridge to be fed next alternating from the left and right columns. This is typically used with most modern magazines for assault rifles and submachineguns.

The second terminates the feed with a single cartridge. This is typically found in semi-automatic pistols. Hugo Schmeisser was the first to invent such a magazine for use with his MP18 and MP28 designs. This arrangement of turned out to be an unhappy one. The magazine was prone to misfeed the catridge as the lips deformed from the stresses of holding back so many rounds, and the tight springs required to exert enough force to overcome the friction generated by the guide walls. The tight spring also resulted in the requirement of a magazine loading tool to assist the user in overcoming these forces.^[1]

Double column magazines also are more prone to jam than single column magazines. More force is exerted outwards against the magazine wall by ammunition cartridges in the two-column geometry.

A double double stack, four column magazine- 50 round box magazine- in available in the Spectre M4.