Moore's Teat-fire cartridge was designed to skirt the patents owned by Horace Smith and Daniel Wesson, who had a monopoly on self-primed pistol cartridges circa 1860. The Teat-fire cartridges did not have a rim at the back like conventional cartridges, but were rounded at the rear, with a small "teat" that would protrude through a tiny opening in the rear of the cylinder. The priming mixture was contained in the teat and when the hammer struck it, the cartridge would fire. (Thus, it was akin to a rimfire cartridge, but instead of having priming all the way around the edge of the rim, it is centrally located in the teat.)
Moore's Caliber .32 Teat-fire Pocket Revolver proved very popular during the American Civil War, with both soldiers and civilians. National Arms produced about 30,000 of the Caliber .32 Teat-fire revolvers from 1864 to 1870, when it was acquired by Samuel Colt's firm.