Percussion cap definitions

Percussion cap

1) Early modern firearm 2) Source of an explosive charge
Found on https://www.crosswordclues.com/clue/percussion-cap

The percussion cap, introduced circa 1820, was the crucial invention that enabled muzzleloading firearms to fire reliably in any weather. Before this development, firearms used flintlock ignition systems which produced flint-on-steel sparks to ignite a pan of priming powder and thereby fire the gun`s main powder charge (the flintlock mechanism re....
Found on http://en.wikipedia.org/wiki/Percussion_cap

percussion cap

(from the article `bullet`) By the 1860s, percussion caps, which detonate upon being struck a sharp blow by the firing pin of a gun, had been incorporated into a metal cartridge ... ...action; in the other, a primer charge of fulminate of mercury was exploded in the cartridge rim. Later improvements changed the point of impact ... Su...
Found on http://www.britannica.com/eb/a-z/p/43

Percussion Cap

The idea of detonating pellets or percussion caps was conceived by Forsyth, an Aberdeenshire clergyman in 1807, introduced in 1816 and adopted by the British government in 1839. They are small, hat-shaped cups filled with detonating powder such as fulminate of mercury with potassium chlorate.
Found on http://www.probertencyclopaedia.com/browse/FP.HTM