Mk 19 Mod 3 40mm Automatic Grenade Launcher in Action

Training video of US Soldiers & US Marines during participating in a live-fire range using the MK19 40mm Grenade Launcher (some footage includes the FGM-148 Javelin, BGM-71 TOW Missile). The purpose of the range was to maintain proficiency with their weapon systems and executing the heavy machine gun course of fire to increase proficiency with the weapon system and prepare for future readiness.

The Mk 19 grenade launcher (pronounced Mark 19) is an American 40 mm belt-fed automatic grenade launcher. The first model (Mod 0) in 1966 was determined to be unreliable and unsafe, but a total of six Mod 1 launchers were successfully tested on U.S. Navy riverine patrol craft in the Mekong Delta in 1972. The Navy made further improvements to the weapon, resulting in the Mod 3 in 1976. The Mod 3 was adopted by the U.S. Army in 1983 and remains in service to the present day.

The Mk 19 automatic grenade launcher replaced the earlier Mk 18 hand-cranked multiple grenade launcher. The 40 mm ammunition used (40×53 mm) is not interchangeable with that used in the M203 (40×46 mm). The M203 ammunition develops a lower chamber pressure, and resultant lower muzzle velocity and range, compared to ammunition loaded for the Mk 19. The Mk 19 fires from an open bolt. The rounds are mechanically fed onto the bolt face with the pull of the charging handles. When the trigger is pressed, the bolt closes, and the firing pin is released. The recoil blows back the bolt, feeds a new round onto the bolt face, which pushes the expended casing off the bolt face.