Following its success in trials, the Colt pistol was formally adopted by the Army on March 29, 1911, when it was designated Model of 1911, later changed to Model 1911, in 1917, and then M1911, in the mid-1920s. The Director of Civilian Marksmanship began manufacture of M1911 pistols for members of the National Rifle Association in August 1912. Approximately 100 pistols stamped "N.R.A." below the serial number were manufactured at Springfield Armory and by Colt. The M1911 was formally adopted by the U.S. Navy and Marine Corps in 1913. The .45 ACP "Model of 1911 U.S. Army" was used by both US Army Cavalry troops and infantry soldiers during the United States' Punitive Expedition into Mexico against Pancho Villa in 1916.