General Dynamics Armament and Technical Products produces the MK19 MOD 3 air-cooled system, a blow-back operated, belt-fed, crew-served 40mm grenade machine gun. Highly portable within small soldier units, the weapon’s high lethality and broad versatility make it the prime choice of the U.S. Armed Forces as an essential weapon in both offen­sive and defensive operations.

Firing M430 High Explosive Dual Purpose grenades, the MK19 pro­vides lethal fire against a variety of targets, including lightly armored vehicles and dismounted infantry. It will penetrate 75mm rolled homog­enous armor at a maximum range of 2,050 meters. Dismounted per­sonnel, within a radius of 15 meters from impact, will be immobilized by blast and fragmentation.
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Features:
• Sustained automatic or single-shot firing
• Dual spade grips for stable control
• Removable barrel
• No headspace or timing adjustments required
• Open-bolt firing eliminates cook off, enhances cooling between bursts and allows sustained firing at three- to five-round bursts
• Simple design for easy maintenance
• Mean rounds between failure exceeds 20,000 rounds

Specifications:
Caliber: 40mm
Weight: 72.5 pounds (33 kg)
Length: 43.1 inches (1,095mm)
Width: 13.4 inches (340mm)
Rate of fire: 300-400 rounds per minute
Ammunition: M430 high explosive dual purpose
(anti-armor and anti-personnel);
MK281 MOD 0 TP Cartridge (TP-training); CS/OC (non-lethal); M918 (flashbang, training)
Maximum effective range: 1,650 yards (1,500m)
Maximum range: 2,242 yards (2,050m)
Muzzle velocity: 790 feet (241m) per second

Source: General Dynamics