Abstract: Apparatus for the simulated shooting of small arms comprises a miniaturized electrical energy source for a radiation emitter which is capable of being accommodated within a dummy cartridge or within the gun barrel. The source can be a capacitor slidably located within the dummy cartridge and which co-operates with a barrel unit housing a switch section, an electronics section, and a pulsed infra-red emitter. On firing the gun the capacitor is propelled forwards by the firing pin of the gun until a probe-like switch portion on the capacitor contacts a corresponding switch portion on the barrel unit so actuating the emitter to give a series of timed pulses which pass through a lens system.