For the Volcanic rifle, Smith added a primer charge to Hunt's "Rocket Ball" and thus created one of the first fixed metallic cartridges which incorporated bullet, primer and powder in one self-contained unit. While still with the company Smith went a step further and added a cylindrical copper case to hold the bullet and powder with the primer in the case rim, thus creating one of the most significant inventions in firearms history, the metallic rimfire cartridge.Smith's cartridge was derived largely from the Flobert BB Cap, but the Flobert design contained no powder. The cylindrical case was in all likelihood inspired by another French design, the Lefaucheux pinfire cartridge. Smith's cartridge, the .22 Short, would be introduced commercially in 1857 with the landmark Smith & Wesson Model 1 revolver and is still manufactured today.
