<P> The percussion cap replaced the flint, the steel "frizzen", and the powder pan of the flint - lock mechanism . It was only generally applied to the British military musket (the Brown Bess) in 1842, a quarter of a century after the invention of percussion powder and after an elaborate government test at Woolwich in 1834 . The first percussion firearm produced for the US military was the percussion carbine version (c. 1833) of the M1819 Hall rifle . </P> <P> The discovery of fulminates was made by Edward Charles Howard (1774--1816) in 1800 . The invention that made the percussion cap possible using the recently discovered fulminates was patented by the Rev. Alexander John Forsyth of Belhelvie, Aberdeenshire, Scotland in 1807 . </P> <P> This early system coined "Percussion Lock" operated in a near identical fashion to flintlock firearms and utilized fulminating primer made of fulminate of mercury, chlorate of potash, sulphur, and charcoal, which was ignited by concussion . It was an invention born of necessity: Rev. Forsyth had noticed that sitting birds would startle when smoke puffed from the powder pan of his flintlock shotgun, giving them sufficient warning to escape the shot . His invention of a fulminate - primed firing mechanism deprived the birds of their early warning system, both by avoiding the initial puff of smoke from the flintlock powder pan, as well as shortening the interval between the trigger pull and the shot leaving the muzzle . </P> <P> Fulminate - primed guns were also less likely to misfire than flintlock guns . However, it was not until after Forsyth's patents expired that the conventional percussion cap system was developed . The percussion cap helped lead to the self - contained cartridge, where the bullet is held in by the casing, the casing is filled with gunpowder, and a primer is at the end . </P>

What is the difference between #10 and #11 percussion caps