Probably no invention connected with firearms has wrought such changes in the principle of gun construction as those effected by the "expansive cartridge case". This invention has completely revolutionized the art of gun making, has been successfully applied to all descriptions of firearms and has produced a new and important industry: that of cartridge manufacture. Its essential feature is preventing gas from escaping the breech when the gun is fired, by means of an expansive cartridge case containing its own means of ignition. Previous to this invention shotguns and sporting rifles were loaded by means of powder flasks and shot bags or flasks, bullets, wads, and copper caps, all carried separately. One of the earliest efficient modern cartridge cases was the pinfire cartridge, developed by French gunsmith Casimir Lefaucheux in 1836.Kinard, Jeff (2004) Pistols: An Illustrated History of Their Impact, ABC-CLIO, p. 109 It consisted of a thin weak shell made of brass and paper that expanded from the force of the explosion. This fit perfectly in the barrel and thus formed an efficient gas check. A small percussion cap was placed in the middle of the base of the cartridge and was ignited by means of a brass pin projecting from the side and struck by the hammer. This pin also afforded the means of extracting the cartridge case. This cartridge was introduced in England by Lang, of Cockspur Street, London, about 1845.
