Mitrailleuse
A mitrailleuse (; from French "mitraille", "grapeshot") is a type of volley gun with multiple barrels of rifle calibre that can fire either multiple rounds at once or several rounds in rapid succession. The earliest true mitrailleuse was invented in 1851 by Belgian Army captain Fafschamps, 10 years before the advent of the Gatling gun. It was followed by the Belgian Montigny mitrailleuse in 1863. Then the French 25 barrel ""Canon à Balles"", better known as the Reffye "mitrailleuse", was adopted in great secrecy in 1866. It became the first rapid-firing weapon deployed as standard equipment by any army in a major conflict when it was used during the Franco-Prussian War of 1870–71. A steel block containing twenty-five 13 mm (.51 calibre) centre-fire cartridges was locked against the breech before firing. With the rotation of a crank, the 25 rounds were discharged in rapid succession. The sustainable firing rate of the Reffye mitrailleuse was 100 rounds per minute. The maximum effective range of the Reffye "mitrailleuse" was about 2000 yards; a distance which placed their batteries beyond the reach of Prussian Dreyse needle rifle fire. Reffye mitrailleuses were deployed in six gun batteries and were manned by artillery personnel. They were not infantry support weapons, but rather a form of special artillery.
Minigun
The ancestor to the modern minigun was a hand cranked mechanical device invented in the 1860s by Richard Jordan Gatling. Gatling later replaced the hand-cranked mechanism of a rifle-caliber Gatling gun with an electric motor, a relatively new invention at the time. Even after Gatling slowed down the mechanism, the new electric-powered Gatling gun had a theoretical rate of fire of 3,000 rounds per minute, roughly three times the rate of a typical modern, single-barreled machine gun. Gatling's electric-powered design received U.S. Patent #502,185 on July 25, 1893. Despite Gatling's improvements, the Gatling gun fell into disuse after cheaper, lighter-weight, recoil and gas operated machine guns were invented; Gatling himself went bankrupt for a period.