The Berthier carbine (French: Mousqueton Berthier) was a French service rifle adopted in 1892, which was chambered in 8x50mmR Lebel and was widely used during the First and Second World War.
The French Army held a series of rifle trials in 1887 to select a suitable carbine. One of the prototypes submitted was designed by Émile Berthier, a mechanical engineer in La Compagnie Bône-Guelma (one of the five subsidiary companies of the Algerian Railway System). Berthier's design was adopted in 1890. The search for a suitable small arm for mounted troops was given greater urgency by the Germans' development of the Karabiner Modell 1888, a carbine variant of the Gewehr 1888. It was issued to essentially all French artillery and cavalry troops.
The Berthier carbines (and later the rifles) used a lighter, streamlined receiver and a one-piece stock that departed from the Lebel Mle 1886/M93 rifle system. For instance, the locking lugs present on the bolt of Berthier weapons do lock into the receiver vertically, instead of horizontally as in the Lebel rifle. Like the Mle 1886/M93, the Berthier carbine was designed for the 8mm Lebel cartridge, but it was loaded by a three round en-bloc Mannlicher-style clip. In line with the usual Mannlicher magazine design, designers included a large opening at the bottom of the magazine well, in part to verify if the carbine was loaded with a charger of cartridges. During World War I, after complaints from combat troops regarding the limited capacity of the 3-round charger and mud ingress into the well opening, the Berthier's magazine was increased to hold a 5 round "en bloc" charger. Furthermore, a hinged metal plate covering the bottom opening of the magazine well was added. The final result was the Mle 1892 M16 5-shot carbine which was well received, but did not appear on the front lines until the summer of 1918. Though inferior overall to Mauser's double-column box magazines, the Berthier weapons had to retain the Mannlicher en bloc system, as the rimmed and tapered 8mm Lebel cartridge could not feed properly from a Mauser-style box magazine. The Berthier Mle 1892 M16 carbine, with a 5-round charger, had a deserved reputation of solidity and reliability that kept it in service until the early 1960s.