United States of America
40 mm Mark 19 Grenade MG
Updated 22 December 2006

Automatic grenade launcher developed by the Navy for Riverine Craft and used today mainly as a close-in weapon against small boats.

Quoting from FM 3-22.27:  "Although the MK 19 is a recent entry into the Army’s inventory, development began in 1963.  The first version was a hand-cranked, multiple grenade launcher called the MK 18.  In 1966 the need for more firepower inspired the development of a self-powered 40-mm machine gun called the MK 19, MOD 0.  This model was neither reliable nor safe enough for use as a military weapon system.  Product improvements begun in 1971 resulted in the 1972 MOD 1, of which only six were produced.  The MOD 1 performed effectively in Navy riverine patrol craft and broader applications for the MK 19 were found.  In 1973 the Navy developed the MOD 2, which featured improved reliability, safety, and maintainability.  In 1976 a complete redesign resulted in the MK 19, MOD 3, which the Army adopted in 1983.  The Army now uses the MK 19 within the tactical environment for defense, retrograde, patrolling, rear area security, urban operations, and special operations."


40 mm Mark 19 on USS Hopper DDG-70 in September 2006
Note the 25 mm Mark 38 in the background
U.S. Navy Photograph 060906-N-9851B-002


Operations Specialist 2nd Class Matthew Burton manning a Mark 96 combination 25 mm cannon and 40 mm grenade launcher on USS Chinook PC-9 in March 2003
Note the feed mechanism for the Mark 19 Grenade Launcher
U.S. Navy Photograph No. 030321-N-0000G-009


40 mm Mortar in October 2006
Note the empty shell cases
U.S. Navy Photograph No. 061009-N-4265O-004

Gun Characteristics
Designation 40 mm Mark 19 Mod 3 Grenade MG
First Ship Class Used On Patrol Boats
Date Of Design Mod 3:  1976
Date In Service Mod 3:  1977
Gun Weight 72.5 lbs. (32.9 kg)
Gun Length oa 43.1 in (1.095 m)
Bore Length 85.6 in (2.175 m)
Rifling Length N/A
Grooves N/A
Lands N/A
Twist N/A
Chamber Volume N/A
Rate Of Fire Cyclic:  325 - 375 rounds per minute
Rapid:  60 rounds per minute
Sustained:  40 rounds per minute
Note:  Mean rounds between failure exceeds 20,000 rounds.
Type Fixed
Weight of Complete Round 11.6 oz (0.33 kg)
Projectile Types and Weights M430 HE-DP - N/A
(anti-armor and anti-personnel)
Bursting Charge 1.6 oz (45 g) RDX
Projectile Length N/A
Complete Round:  4.4 in (11.2 cm)
Propellant Charge N/A
Cartridge 40 x 53 mm
Muzzle Velocity 794 fps (242 mps)
Working Pressure N/A
Approximate Barrel Life
(see Note 3)
Ammunition stowage per gun 62 rounds in M548 metal container
42 rounds in PA120 metal container

1) The M383 round originally issued for these weapons is obsolescent and rarely found in active units.

2) Warhead does not arm until it has traveled about 20 to 33 yards (18 to 30 m).  M430 has an anti-personnel radius of 17 yards (15 m).

Effective Range @ 15 degrees at point target 1,650 yards (1,500 m)
Maximum Range @ 25 degrees at area target 2,240 yards (2,050 m)
Armor Penetration with M430
About 2.0 in (51 mm) of hardened steel at 0 degrees obliquity at any range.
Mount / Turret Data
Designation Single:  N/A
Weight Gun and cradle:  99 lbs. (44.9 kg)
Elevation 0 / +70 degrees
Rate of Elevation Manual operation, only
Train 360 degrees
Rate of Train Manual operation, only
Gun Recoil N/A
Data from
"Jane's Ammunition Handbook:  Ninth Edition 2000-2001" edited by Terry J. Gander and Charles Q. Cutshaw
FM 3-22.27 (FM 23.27) "MK 19, 40-mm Grenade Machine Gun, MOD 3:  November 2003" distributed by Headquarters, Department of the Army
Federation of American Scientists (FAS)
General Dynamics Press Releases
United Defense Press Releases
US Navy Fact File