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 1870, in an infantry support role and at shorter distances, it produced devastating effects.