text: The term derringer () has become a genericized misspelling of the last name of Henry Deringer. Many copies of the original Philadelphia Deringer pistol were made by other gun makers worldwide, and the name was often misspelled; this misspelling soon became an alternative generic term for any pocket pistol, along with the generic phrase palm pistol, which Deringer's competitors invented and used in their advertising. With the advent of metallic cartridges, pistols produced in the modern form are still commonly called "derringers".
  Daniel Moore patented a single shot metallic cartridge .38 Rimfire derringer in 1861. These pistols have barrels that pivoted sideways on the frame to allow access to the breech for reloading. Moore would manufacture them until 1865, when he sold out to National Arms Company which produced single shot .41 Rimfire derringers until 1870, when it was acquired by Colt's Patent Firearms Manufacturing Company. Colt continued to produce the .41 Rimfire derringer after the acquisition, as an effort to help break into the metallic-cartridge gun market, but also introduced its own three single shot Colt Derringer Models, all of them also chambered in the .41 Rimfire cartridge. The last model to be in production, the third Colt Derringer, was not dropped until 1912. The third Colt Derringer Model was re-released in the 1950s for western movies, under the name of Fourth Model Colt Deringer.