The Chauchat was the standard light machine gun or "machine rifle" of the French Army during World War I (1914–18). Its official designation was "Fusil Mitrailleur Modèle 1915 CSRG". Beginning in June 1916, it was placed into regular service with French infantry, where the troops called it the FM Chauchat, after Colonel Louis Chauchat, the main contributor to its design. The Chauchat in 8mm Lebel was also extensively used in 1917–18 by the American Expeditionary Forces (A.E.F.), who described the weapon as "Abysmal", where it was officially designated as the "Automatic Rifle, Model 1915 (Chauchat)". A total of 262,000 Chauchats were manufactured between December 1915 and November 1918, including 244,000 chambered for the 8mm Lebel service cartridge, making it the most widely manufactured automatic weapon of World War I. The armies of eight other nations—Belgium, Finland, Greece, Italy, Poland, Romania, Russia, and Serbia—also used the Chauchat machine rifle in fairly large numbers during and after World War I.