View Full Version : 40mm Auto Grenade Launcher

Harley Nolden
February 27, 2001, 08:27 AM
Back in the mid to late 80's I was the resident gunsmith for the Army when they were testing a 40mm (grenade launcher)in full auto. It could be mounted to just about anything and although, during testing, did not perform well, I understand it is now a part of the Military Arsenal.

During a discussion of this piece, with another branch of service member, it was noted that this particular gun was said to have been Battle Tested in Vietnam by Navy Seals, from aircraft in 1969.

Having been there, Viet Nam in 1969 as an advisor, and having to use air stikes, I don't recall this gun ever being used or hear of its existance. Can someone enlighten or refresh my deteriating memory.


Steven Mace
February 27, 2001, 09:55 AM
Harley, you're possibly refering to the following?

MK19 40mm Machine Gun, MOD 3


Manufacturer: Saco Defense Industries
Length: 43.1 inches (109.47 centimeters)
Gun: 72.5 pounds (32.92 kilograms)
Cradle (MK64 Mod 5): 21.0 pounds (9.53 kilograms)
Tripod: 44.0 pounds (19.98 kilograms)
Total: 137.5 pounds (62.43 kilograms)
Muzzle velocity: 790 feet (240.69 meters) per second
Bore diameter: 40mm
Maximum range: 2200 meters
Maximum effective range: 1600 meters
Rates of fire:
Cyclic: 325-375 rounds per minute
Rapid: 60 rounds per minute
Sustained: 40 rounds per minute
Unit Replacement Cost: $13,758

Features: The MK19 40mm machine gun, MOD 3 is an air-cooled, disintegrating metallic link-belt fed, blowback operated,
fully automatic weapon and is crew transportable over short distances with limited amounts of ammunition. It can fire a variety
of 40mm grenades. The M430 HEDP 40mm grenade will pierce armor up to 2 inches thick, and will produce fragments to kill
personnel within 5 meters and wound personnel within 15 meters of the point of impact. Associated components are: MK64
Cradle Mount, MOD 5; M3 Tripod Mount; and the AN/TVS-5 Night Vision Sight. The MK19 also mounts in the up-gunned
weapons station of the LVTP7A1 model of the AAV and vehicle ring mounts.

Background: The MK19 was originally developed to provide the U.S. Navy with an effective riverine patrol weapon in
Vietnam. A Product Improvement Program was initiated in the late 1970s resulting in the MK19 Mod 3.


Just my guess?

Steve Mace

Daniel Watters
February 27, 2001, 10:07 AM
There were a couple of different designs. Some were set up for 40x46mm (the same used in the M79 and M203), while others were designed for the high-velocity 40x53mm.

The MK18 40x46mm and MK19 (Mod 0 and Mod 1) 40x53mm were both used by the US Navy in Vietnam. I'm not certain as to the origin of the MK18, but the US Naval Ordnance Station in Louisville, KY is credited with the MK19. The MK 19 Mod 0 would have been available in 1967, while the MK 19 Mod 1 would have been ready around 1971.

The US Army used the M75 automatic grenade launcher mounted in the M5 chin turrets for the UH1 and CH47 gunship conversions. (I am not certain whether these were 40x46mm or 40x53mm.) The AH1 Cobra's M28 chin turret paired the M75 (and later, the M129) grenade launcher with a M134 Minigun. The M129 was also mounted in the XM8 armament subsystem pod, primarily used by the OH6 and OH58. The Army even played with a door mounted M129: the XM94. It is my understanding that the M129 was chambered for the 40x53mm grenades.

I suspect that the weapon you saw tested in the '80s was the updated MK19 Mod 3.

Harley Nolden
February 27, 2001, 10:36 AM
Bingo, Bango and double darn. YOu hit it right on the head. The photo provided brought it back. Thanks a heap.

Ain't dis da goodest web site to get info



Mike Irwin
February 27, 2001, 11:19 AM
I saw one of these fired during a military demonstration I was at a couple of years ago.

Talk about neat toy!

February 27, 2001, 12:55 PM
MK 19 best thing since sliced bread, miniskirts and canned beer. 350 RPM cyclic rate of fire. Can fire a belt out to max range (2200m) and watch the hillside erupt!!! Great anti-sniper weapon - does it to them before they do it to you.