|M320 Grenade Launcher Module|
|Place of origin||United States and Germany|
|Used by||See Users|
|Wars||War in Afghanistan (2001-2021)|
|Manufacturer||Heckler & Koch|
|Mass||1.5 kg (3.3 lb)|
|Length||350 mm (3.7 in.)|
|Barrel length||280 mm (1 in.)|
|Action||Single shot, double action|
|Rate of fire||5 to 7 rounds per minute|
|Muzzle velocity||76 m/s|
|Effective firing range||150 m (point)|
350 m (area)
|Maximum firing range||400 m|
|Feed system||Single shot|
M320 Grenade Launcher Module (GLM) is the U.S. military's designation for a new single-shot 40 mm grenade launcher system to replace the M203 for the U.S. Army, while other services initially kept using the older M203. The M320 uses the same High-Low Propulsion System as the M203.
In 2004, the Army announced a requirement for a commercial off-the-shelf 40 mm grenade launcher. It had to be more reliable, ergonomic, accurate, and safer than the M203. It had to be able to fire all 40 mm low-velocity grenades, but be loaded from the breech to accept future longer projectiles. Heckler & Koch's submission was selected in May 2005.
After the U.S. Army at Picatinny Arsenal conducted a competitive bidding process for a new 40 mm grenade launching system, Heckler & Koch was awarded a contract to provide the XM320 beginning in 2006. The M320 was developed from but is not identical to the Heckler & Koch AG36 (a key distinguishing feature being the addition of a folding foregrip ahead of the trigger for use when the weapon is in stand-alone configuration, a feature the AG36 lacks). The M320 entered production in November 2008.
Fielding of the M320 was planned to begin in February 2009, with 71,600 GLMs planned to phase out the M203 by 2015. The weapon was officially fielded in July 2009 at Fort Bragg by the 1st Brigade Combat Team, 82nd Airborne Division. In June 2017, Bravo Company, 2nd Combat Engineer Battalion became the first U.S. Marine Corps unit to be issued the M320. Following initial experiments, the Marines expect to issue 7,000 launchers between 2019 and 2022.
The M320 has three major parts: a grenade launcher with rifled barrel, Day/Night Sight (DNS) produced by Insight Technology, Inc and a hand held Laser Range Finder (LRF). Some of the benefits are:
The M320 is based on the earlier Heckler & Koch AG-C, but with some Army-specific modifications. It includes a folding foregrip and shorter barrel for a more compact package. The sights had to be reconfigured to shoot accurately with the slightly different ballistics from the shorter barrel length. The system was supposed to be lighter than the M203 (it is actually slightly heavier) and does not require specific mounting hardware. Breech loading allows the grenadier to load a shell while keeping the sight on target. It weighs 3.57 lb (1.62 kg) in its base configuration, 3.89 lb (1.76 kg) with the LRF and electronic sight, and 4.8 lb (2.2 kg) with the stock attached. The sights on the M320 are located to the side of the launcher, avoiding the problems that the M203 had with its sight design, which were mounted on top of the launcher and could interfere with the rifle's sights, so they had to be attached separately. This meant two separate operations had to be performed when adding the grenade launcher to the weapon, and since the sights were not integral to the M203, they had to be re-zeroed every time the launcher was reattached to the rifle. The LRF helps eliminate range estimation errors common in shots greater than 100 meters, thus increasing first round hit probability.
The M320 can fire all NATO high-explosive, smoke, and illumination grenades. Its breech opens to the side, allowing it to fire a variety of newer rounds which are longer, in particular certain non-lethal rounds, such as Federal Laboratories' "exact impact" (brand name) non-lethal sponge batons or sponge grenades. The M320 operates in double-action mode, with an ambidextrous safety. In case of misfire, the M320 operator merely has to pull the trigger again. The M203 used a single-action mode, which cocks the weapon as the barrel is opened. The M203 operator has to open the barrel by unlocking it and pushing forward to cock the weapon and then re-close the barrel, then pull the trigger again. The problem with this is that in opening the barrel, the grenade is designed to eject and the operator must ensure that it does not fall to the ground.
The M320 is one of two 40 mm grenade launchers capable of firing Pike Missile (developed by Raytheon) without modification--the other being the FN EGLM (Enhanced Grenade Launching Module) developed for the FN SCAR.
Nonetheless, the weapon's introduction was not without criticism: