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.
Montigny mitrailleuse
Napoleon III showed personal interest in the mitrailleuse. Montigny had approached the French army for the purpose of a sale. Experiments to evaluate the weapon began in 1863 in a French facility near Paris but the decision was made to build a similar weapon by sole French means. Manufacture began at Meudon in 1866 under the direction of Verchères de Reffye and the undisclosed assistance of Montigny. Hence the weapon is usually known as the "Reffye mitrailleuse". Altogether 215 mitrailleuses were manufactured for the French Army before the Franco-Prussian War of 1870-71. They were of the 13mm, 25-barrels type, and used elongated shotgun shell style cartridges instead of foil cartridges as in the Montigny mitrailleuse. The weapon, which was on an artillery carriage, was deployed in six gun batteries and manned by artillery personnel. Most of the time, they were used quite ineffectively to engage distant targets. When the weapon was engaged at the Battle of Gravelotte in 1871, in an infantry support role and at shorter distances, it produced devastating effects.