Chauchat M1918 CSRG

The Chauchat M1918 CSRG is the United States .30-06 Springfield rechambered version of the French Fusil Mitrailleur Mle 1915 Chauchat light machine gun, produced by the Gladiator factory in Le Pre-Saint-Gervais for the American Expeditionary Forces in the final year of the First World War. Rather than rebarreling the existing 8mm Lebel design, the M1918 was a purpose-built variant: it abandoned the distinctive semicircular curved magazine of the original in favor of a near-straight 16-round box magazine suited to the rimless .30-06 cartridge, and it featured a modified magazine well and a relocated foregrip. Like the parent weapon it operated on the unusual long-recoil principle - shared with John Browning's Remington Model 8 from which the action was derived - in which the entire barrel and bolt recoil rearward together before separating and returning independently, producing a heavy reciprocating sensation and a slow cyclic rate of roughly 240 rounds per minute. Weighing approximately 9 kg with an overall length of 1,143 mm and a 470 mm finned barrel inside a perforated cooling jacket, it was fired from an integral bipod using a pistol grip and wooden shoulder stock, with a selector for semi-automatic and full-automatic fire. The M1918 became notorious as one of the worst-functioning weapons fielded by American forces: its chambers were reamed too short for the higher-pressure .30-06 cartridge, causing chronic extraction failures and stuck cases once the gun heated up, and the AEF withdrew most examples from service within months in favor of the M1918 Browning Automatic Rifle. Over 19,000 M1918 Chauchats were manufactured.