Volley gun
The Ribauldequin was a medieval version of the volley gun. It had its barrels set up in parallel. This early version was first employed during the Hundred Years' War by the army of Edward III of England, in 1339. Later on, the late Swiss army employed it.
Colt 1851 Navy Revolver
The first metallic cartridge revolver made by Colt was the Thuer-Conversion Model Revolver, a design that would not require a cylinder with cylindrical chambers so as not to infringe on the Rollin White patent. A small number (about 1000–1500) of Model 1851 Navy revolvers was converted, using front-loaded, slightly tapered cartridges to fit the chambers of the cylinder reamed to a slight taper.