When cartridges are introduced into a weapon there exists the danger that the conical shoulder of the cartridge case or sleeve will be deformed to an undesired degree. To avoid such disadvantage the wall of the conical shoulder is constructed to be thicker than the wall of the case or sleeve body of the cartridge case. For producing such a cartridge case an extruding mandrel is used which contains a recess at the region of the conical shoulder in order to generate a region of increased wall thickness in the wall of the cartridge case or sleeve.