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.
Wildey
The Wildey was purpose-designed to be a hunting firearm. The pistol is built to withstand breech pressures of over 48,000 PSI associated with Moore's lines of proprietary cartridges. The Wildey was the first gas-operated double action semi-automatic pistol.