Aircraft / Aviation Vehicles & Artillery Small Arms Warships & Submarines Military Ranks Military Pay Chart (2024) Special Forces
Infantry Small Arms / The Warfighter

Heckler & Koch HK GMG (GMW / GraMaWa)

Automatic Grenade Launcher (AGL) [ 1996 ]

The Heckler & Koch HK GMG makes use of the high-velocity 40x53mm grenade through a repeat-fire function.

Authored By: Staff Writer | Last Edited: 05/17/2022 | Content ©www.MilitaryFactory.com | The following text is exclusive to this site.

The Heckler & Koch GMG ("GranatMaschinenWaffe" or "GraMaWa") is a 40mm automatic grenade launcher similar in form and function to the American Mk 19 series. It fires a high-velocity 40x53mm grenade in various warhead types to suit mission requirements. The high-velocity form contrasts the 40x46mm low-velocity series found in several shoulder-fired weapons. The high-velocity version is primarily reserved for vehicle-mounted guns. As such, the GMG is an oversized automatic grenade projector usually fitted to a heavy duty pintle mounting or tripod assembly.

Overall dimensions include a running length of 1,090mm with a barrel of 415mm long. The field version of the weapon consists of the 29kg gun system and 11kg tripod. The automatic nature of the weapon utilizes a recoil-based API (Advanced Primer Ignition) blowback action consistent with cannon caliber types 20mm and larger. Through the API action, the primer is ignited while the bolt is still in motion (moving forward) during which the cartridge is still being seated into the chamber. The bolt moves both forward and backward in the action, allowing for a reduced recoil force to be achieved which serves an automatic weapon such as this very well. The GMG can achieve a rate-of-fire of 350 rounds per minute and fires each grenade at a muzzle velocity of 790 feet per second out to an effective range of 1,500 meters and maximum engagement range of 2,200 meters. The GMG is fed by a 32-round disintegrating link belt usually held in an accompanying ammunition box. Feeding is through the right side of the receiver with spent casings ejected through a port on the left side. A carrying handle is fitted at the base of the barrel while additional aiming handles are present at the rear of the receiver. The barrel is capped by a long slotted muzzle brake. While fitted with standard iron sights, a reflex optical sight is also provided.

The GMG was designed by engineers at Heckler & Koch from 1992 to 1995 before seeing adoption by German Army forces in 1996. The series continues production today (2013) and is in the inventories of Canada (as the licensed-produced Rheinmetall-Canada "C16 CASW"), Finland (as the "40 KRKK 2005"), Greece, Ireland, Latvia, Lithuania, Netherlands, New Zealand, Norway, Poland, Portugal, Slovenia, the United Kingdom (as the "L134A1") and the United States (under SOCOM).©MilitaryFactory.com
Note: The above text is EXCLUSIVE to the site www.MilitaryFactory.com. It is the product of many hours of research and work made possible with the help of contributors, veterans, insiders, and topic specialists. If you happen upon this text anywhere else on the internet or in print, please let us know at MilitaryFactory AT gmail DOT com so that we may take appropriate action against the offender / offending site and continue to protect this original work.


Heckler & Koch GmbH - Germany
Canada; Finland; Germany; Greece; Ireland; Latvia; Lithuania; Malaysia; Netherlands; New Zealand; Norway; Poland; Portugal; Slovenia; United Kingdom; United States
Operators National flag of Canada National flag of Finland National flag of modern Germany National flag of Greece National flag of Ireland National flag of Latvia National flag of Lithuania National flag of Malaysia National flag of the Netherlands National flag of New Zealand National flag of Norway National flag of Poland National flag of Portugal National flag of Slovenia National flag of the United Kingdom National flag of the United States
Service Year
National Origin

Capable of suppressing enemy elements at range through direct or in-direct fire.
Qualities of this weapon have shown its value to Special Forces elements requiring a versatile, reliable solution for the rigors of special assignments.

1,090 mm
(42.91 inches)
Overall Length
415 mm
(16.34 inches)
Barrel Length
104.72 lb
(47.50 kg)
Empty Weight
API Blowback; Automatic
Gas pressure from the rearward movement of the ignited cartridge case provides the needed bolt movement, ejecting the spent case and stripping a fresh case from the magazine.
May not represent an exhuastive list; Calibers may be model-specific dependent; Always consult official manufacturer sources.
32-round disintegrating belt
Iron; Optional Optics.

Material presented above is for historical and entertainment value and should not be construed as usable for hardware restoration, maintenance, or general operation - always consult official manufacturer sources for such information.

5,000 feet
(1,524 meters | 1,667 yards)
Max Effective Range
790 ft/sec
(241 m/sec)
Muzzle Velocity

Granatmaschinengewehr (GMW / GraMaWa) - Base Series Designation.
C16 CASW ("Close Area Suppression Weapon") - Canadian Army designation.
40 KRKK 2005 - Finnish Army designation
L134A1 - British Army designation

Military lapel ribbon for the American Civil War
Military lapel ribbon for pioneering aircraft
Military lapel ribbon for the Cold War
Military lapel ribbon for the Korean War
Military lapel ribbon representing modern aircraft
Military lapel ribbon representing special forces
Military lapel ribbon for the Ukranian-Russian War
Military lapel ribbon for the Vietnam War
Military lapel ribbon for the World War 1
Military lapel ribbon for the World War 2


1 / 1
Image of the Heckler & Koch HK GMG (GMW / GraMaWa)
Image copyright HK-USA marketing material.

Disclaimer | Privacy Policy | Cookies

2024 Military Pay Chart Military Ranks DoD Dictionary Conversion Calculators Military Alphabet Code Military Map Symbols

The "Military Factory" name and MilitaryFactory.com logo are registered ® U.S. trademarks protected by all applicable domestic and international intellectual property laws. All written content, illustrations, and photography are unique to this website (unless where indicated) and not for reuse/reproduction in any form. Material presented throughout this website is for historical and entertainment value only and should not to be construed as usable for hardware restoration, maintenance, or general operation. We do not sell any of the items showcased on this site. Please direct all other inquiries to militaryfactory AT gmail.com. No A.I. was used in the generation of this content; site is 100% curated by humans.

Part of a network of sites that includes GlobalFirepower, a data-driven property used in ranking the top military powers of the world, WDMMA.org (World Directory of Modern Military Aircraft), WDMMW.org (World Directory of Modern Military Warships), SR71blackbird.org, detailing the history of the world's most iconic spyplane, and MilitaryRibbons.info, cataloguing military medals and ribbons. Special Interest: RailRoad Junction, the locomotive encyclopedia.

©2023 www.MilitaryFactory.com • All Rights Reserved • Content ©2003-2023 (20yrs)