Abstract: The accessory for training simulators is intended especially for the effeve practice and monitoring of the work of the loading gunner. A practice cartridge (20) has a device (23) for detecting the actuation of the firing mechanism (9, 10) or an electrical firing signal supplied from outside and a device (24) for emitting an electromagnetic signal when this actuation or the firing signal is detected. Furthermore, the practice cartridge (20) has, on its rear side (7), two electrodes (18, 19) which can be bridged by the striking pin (9) and of which one (19) is connected to the device (23) for detecting the actuation of the firing mechanism (9, 10) or the electrical firing signal supplied from outside and the other (18) is connected via a switch (21) to a battery (22) arranged in the practice cartridge (20). The electromagnetic signal is detected and transmitted by a receiver (32) arranged at the barrel muzzle.