airborne troops, and a knife bayonet was added. The MAS-49 built-in rifle grenade launcher was replaced by a combination compensator/rifle grenade launcher that fired NATO-standard 22mm rifle grenades. The rifle also incorporates an integral grenade launching sight that is attached to the front sight block and a gas cutoff that prevents gas from entering the gas tube from the gas port when firing grenade launching blank ammunition. Attempts were made to replace the MAS-49, in the form of the MAS-54 and the FA-MAS Type 62, both 7.62×51mm NATO battle rifles, but neither were successful. The MAS-49/56 ended production in 1978 and was replaced with the 5.56×45mm NATO caliber FAMAS bullpup assault rifle. The MAS-49/56 was withdrawn from service in 1990. Whereas only 20,600 MAS-49 were manufactured, the MAS-49/56 was mass-produced, attaining a total of 275,240 rifles issued between 1957 and 1978. Technical characteristics The direct impingement gas system was first applied in 1901 to a 6mm semi-automatic experimental rifle (the ENT B-5) designed by Rossignol for the French military. Although several experimental prototypes using a tilting bolt and direct impingement had been tested by MAS since 1924, the immediate precursor to the MAS 7.5mm semi-automatic rifle series is the MAS-38/39. It was successfully tested in March 1939, just before World War II, and followed in May 1940 by the nearly identical MAS 1940. Similar direct impingement designs include the Swedish semi-automatic Ag m/42 adopted in 1942, and the US M16 select-fire rifle adopted in 1963. In the AG42B and MAS systems, gas is vented from a port on top of the barrel through a small diameter tube to a hollow located on the front face of the bolt carrier. The contained forces of the gases move the carrier to the rear against the operating spring pressure with enough momentum to open the bolt, and within a short distance the end of the tube is exposed vent to the atmosphere. The M16 system vents gas from the barrel through a tube and into the body of the bolt carrier where it expands. Rings on the bolt body form a seal and the expanding gases move the bolt carrier to the rear, which starts the bolt opening cycle. The spent gases then vent through now exposed holes in the side of the bolt carrier. The MAS system has the advantage of not depositing gas fouling on the bolt itself, a separate part