Rifle magazine with storage container

A firearm magazine comprising:

• a first elongated tubular body defining an ammunition passage;
• the first elongated tubular body having an upper end defining an ammunition feed aperture;
• the first elongated tubular body having a lower end having a first floor plate attachment facility;
• a magazine spring and follower contained in the ammunition passage;
• a floor plate having a first attachment feature adapted to connect to the first floor plate attachment facility;
• a second elongated tubular body separate from the first elongated tubular body and defining a storage passage;
• the second elongated tubular body having an upper end having a second floor plate attachment facility;
• the second tubular elongated body lacking an ammunition feed aperture;
• and
• the floor plate having a second attachment feature adapted to connect to the second floor plate attachment facility.