MK 19 40mm automatic grenade launcher

Originally developed by the U.S. Navy but used by all the military services, the MK 19 Automatic Grenade Launcher/Machine Gun' fires 40mm grenades at area targets, and also can defeat light armored vehicles. Other applications include:
 * Protect motor movements, assembly areas, and supply trains in bivouac.
 * Defend against hovering rotary aircraft.
 * Destroy lightly armored vehicles.
 * Fire on suspected enemy positions.
 * Provide high volumes of fire into an engagement area.
 * Cover obstacles.
 * Provide indirect fires from defilade positions.

The grenades, although fed with a belt rather than singly, are compatible with the single-shot, handheld M79, M203 grenade launcher and M320 grenade launchers. The MK47 advanced lightweight grenade launcher is a variant with better sights and a higher rate of fire, to replace the MK 19 in applications for the United States Special Operations Command.

Mechanically, the gun is air-cooled, blowback-operated, and crew-served. It fits into the same mount that accepts the .50 caliber M2 machine gun and a single-tube BGM-71 TOW antitank missile launcher. Although it can be broken into three pieces -- gun, tripod, and cradle -- like the M2, at 137 pounds/62 kg without ammunition, and ammunition weighing 64 pounds per 48 round box, it is impractical to carry for any distance. The weapon may be carried by a weapon and emplaced on a tripod, but is most commonly fired from a vehicle mount.

Its original use was on U.S. Navy river gunboats in the Vietnam War, which, in turn, derived from a hand-cranked MK 18, similar to the classic Gatling gun, which had too low a rate of fire. Modifications have made it reliable in high heat and sandy conditions.

The standard round of ammunition is High Explosive Dual Purpose (HEDP), which can defeat 50-mm of rolled homogenous armor or 16 inches of concrete. An HE round is also available for engaging troops in the open or other soft targets. Both rounds have a bursting radius of 15 meters and a flat trajectory out to 800 meters. The weapon can be employed in an indirect fire role to engage targets from 800 meters out to the maximum effective range. The methods of controlling indirect fires is the same as the 60mm mortar--direct lay, direct alignment, or an observer to provide corrections and the use of the traverse and elevation mechanism to apply these corrections to the gun.

Offensive tactics
In the offense, the MK19 can be employed similar to the 60 mm mortar in the indirect-fire role and similar to the BGM-71 TOW in the direct-fire role. Individual TOW rounds are far more destructive than 40mm grenades.

The MK19 can be employed from an overwatch position to provide responsive suppressive fires if enemy contact is made. The weapon can also suppress/destroy enemy weapons and positions on the objective prior to the infantry assault. It may also support the isolation of the objective area by blocking likely avenues of approach with concentrated destructive fires.

Defensive tactics
In the defense, the MKI9 can be effective in both the direct and indirect-fire roles. It can be assigned a priority target or an final protective fire just like a 60mm mortar. The enemy will attempt to locate and destroy these weapons early in his attack. Unless the MK19s are employed from defilade/fire from prepared dug-in firing positions, they are very vulnerable. The mobility capability for the MK19 when mounted on the HMMWV must be balanced against the vehicle's vulnerability to detection, and destruction.