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. (US 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. The unit was officially fielded in July 2009 at Fort Bragg by the 1st Brigade Combat Team, 82nd Airborne Division.
| M320 Grenade Launcher Module | |
|---|---|
| Type | Grenade launcher |
| Place of origin | Germany |
| Production history | |
| Manufacturer | Heckler & Koch |
| Unit cost | US$3,500 |
| Specifications | |
| Weight | 1.5 kg (3.3 lb) |
| Length | 350 mm (13.7 in.) |
| Barrel length | 280 mm (11 in.) |
| | |
| Cartridge | 40x46mm SR |
| Action | Single shot, double action |
| Rate of fire | 5 to 7 rounds per minute |
| Muzzle velocity | 76 m/s |
| Effective range | 150 m |
| Maximum range | 400 m |
| Feed system | Single shot |
The M320 has three major parts: a grenade launcher, Day/Night Sight (DNS) produced by Insight Technology, Inc and a hand held Laser Range Finder (LRF). Some of the benefits are:
- The M320 can be used in two ways. It can be attached to the M16 assault rifle and the M4 Carbine, attaching under the barrel forward of the magazine, or it can be used dismounted with a stock attached as a stand alone model.
- The Day/Night Sight allows the grenadier to effectively engage the enemy in the dark.
- The sights on the M320 are located to the side of the launcher. This avoids the problems that the M203 had with its sight design. The M203's sights were mounted on top of the launcher and could interfere with the rifle's sights and 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 M320 can fire all NATO high-explosive, smoke, and illuminating grenades. Its breech opens to the side, allowing it to fire a variety of newer rounds which are longer, in particular certain less-lethal rounds.
- 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 LRF helps eliminate range estimation errors common in shots greater than 100 meters, thus increasing first round hit probability.
