The Chauchat-Ribeyrolles was a French prototype automatic rifle designed by Paul Ribeyrolles and Louis Chauchat.
The Chauchat-Ribeyrolles was developed at the Commission Technique de Versailles in 1918. Short and compact in build, it was designed as a port firing weapon for tanks, and was one of the first examples of such a weapon. It was completed in July of that year and presented for military testing, which lasted until July 1919. The weapon was rejected from service and only a few prototypes were built.
The Chauchat-Ribeyrolles was a gas-operated automatic carbine built from the RSC 1917 rifle. It shortened the overall length of the RSC by removing the stock and cutting down the barrel, and the gas system of the base rifle was replaced by an external gas tube fixed to the right side of the gun that ran from the gas port on the barrel to the bolt. A muzzle brake was fitted to the barrel. The gun fed from 8-round clips, but the magazine cover of the original rifle was ditched, leaving the clip exposed.