The cartridge ammunition (1) comprises a projectile (11) and a cartridge shell (10) receiving the same. The cartridges of the ammunition are magazined in a belt (31) and are pulled out of the belt by means of an unbelting device and transferred into the lock of the automatic firearm so that the individual projectiles (11) can be shot from the automatic firearm at a high shooting frequency. To minimize the forces abruptly exerted on the bottom flange of the cartridge shell (10) by means of the removal of the cartridge ammunition from the belt, at least one recess (33) is provided in the bottom flange (32) of the cartridge shell (10), thus increasing the bending elasticity of the bottom flange, e.g. by reducing the thickness of the bottom flange. The recesses (33) may e.g. be designed as a groove (33a) or as a series of blind bores (33b) that extend in parallel to the edge of the bottom flange.