The humble snap cap
We’ve all got them, plastic ones, chrome ones, brass ones – the ubiquitous snap cap found in every case and sold in every gun shop. They are so common and obvious that nobody ever gives them a second thought but somebody must have invented them.
That somebody was no less than Alexander Henry of Edinburgh. In patent no. 3257 of december 13, 1870, Henry invented the snap cap that has since been in production in its hundreds of thousands.
In his patent he did not refer to it as such preferring the term “dummy cartridge” or “a new and improved blank cartridge”. He stated that the cartridge could be made out of wood, metal or paper with a small centre “pad” in place of the percussion primer and that the pad could be cushioned with either India rubber or a small spring.
In addition to this primary purpose, Henry proposed covering the snap cap with leather or wool saturated in oil to serve as a stopper for dust or damp ingress thereby preserving the bore from rust or corrosion.
The patent drawing for Henry’s snap cap of 1870. A springpowered primer (top) and an India rubber primer (bottom).