A magazine of a pistol for cartridges with a case rim, having a hollow magazine body for accommodating the cartridges in two vertically offset rows, a base plate, a feeder, which is guided in a displaceable manner in the magazine body, and a compression spring between the feeder and the base plate, wherein the upper end region of the magazine body forms a narrowing, in which the two rows of cartridges are guided together to form a single row. In order to ensure a reliable feed of the cartridges despite the case rim, in the longitudinal center the side walls have inwardly directed beads which run over the entire height of the side walls and merge, in the upper region, into converging guide ribs, and the feeder forms a bearing surface, which is convex in the longitudinal direction and on which a cartridge located thereon can alter its angle of inclination in relation to the horizontal.