Several examples of a cartridge magazine system are shown each arranged to hold a plurality of cartridge magazines adjacent to a magazine well of a weapon. The system including several interoperating components, for example: a rigid cylindrical shaft having a center axis aligned with an insert axis of the magazine well, a cartridge magazine holder assembly, and a stop cap at a lower end of the shaft to maintain position of the cartridge magazine holder assembly upon the shaft. One example of the magazine holder assembly including: a collar in contact with the shaft so as to freely reposition along the shaft wherein the collar is rotatable about the shaft. At least one fork extends radially from the collar. Wherein each fork includes a surface for retention of a cartridge magazine in position to be inserted into and removed from the magazine well without removing the magazine from the fork.