The Mk-19 is a belt-fed, blowback-operated, air-cooled, crew-served, fully-automatic weapon that is designed not to cook off. It fires 40 mm grenades at a cyclic rate of 325 to 375 rounds per minute, giving a practical rate of fire of 60 rounds per minute and 40 rounds per minute The weapon operates on the blowback principle, which uses the chamber pressure from each fired round to load and re-cock the weapon. The Mk-19 can launch its grenade at a maximum distance of 2,212 meters, or (2,419 yd). though its effective range to a point target is about 1,500 meters, or (1,600 yd). since the large rear leaf sight is only graduated as far. The nearest safe distance to launch the grenade is 310 meters in training and 75 meters in combat.
Credit US Defense News