Pyrotechnic cocking charge

A pyrotechnic cocking charge is a device used to [...] or re-[...] a gas-operated automatic cannon, such as the Mauser BK-27 or the Gryazev-Shipunov GSh-6-23. Such devices are not necessary in an externally-powered cannon, such as the electrically-driven M61 Vulcan, where the external power source is used to operate the mechanism of the weapon. The number of charges carried varies by design - the GSh-6-23 has a generous complement of ten, while others have as few as one.