M320 Grenade Launcher Module 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 will keep
using the older M203. The M320 uses the same High-Low Propulsion System as the M203.
In 2004, the U.S. Army announced requirements 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.
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.
Overview The M320 has three major parts: a grenade
launcher, Day/Night Sight produced by Insight Technology, Inc and a hand held Laser Range
Finder. 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 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 is lighter than the M203 and does not require specific
mounting hardware. Breech loading allows the grenadier to load a shell while keeping the
sight on target. 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 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" 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 has the ability to fire detached from a rifle. Soldiers have reported difficulties
carrying it unmounted. The grenade launcher comes with a one-point sling, which does not
hold it securely. Carrying by the sling would cause it to bounce around and sometimes be
dragged through dirt. Soldiers wanted to carry the M320 in a holster to provide protection,
rather than just putting it in their rucksack. The Natick Soldier Systems Center began the
M320GL Holster Soldier Enhancement Program in November 2012. Three commercial vendors
produced 167 holsters each. The SEP is using the "buy-try-decide" concept, which allows
the Army to test the functionality of equipment without spending much time on research and
development. One model was bulky and included pockets for grenades, another is more streamlined
and offers less protection for the module, and the third was a mix of the two. Soldiers
from the 75th Ranger Regiment were given a dozen holsters and went through standardized
tests in mid May 2013. The soldiers filled out surveys after the testing. Each of the
holsters had small issues that need adjusting, with none necessarily performing better than
the others. The next step is to test them with an entire brigade. As of July 2013, the
holsters are being evaluated by soldiers in Afghanistan. Project officials will make a
recommendation to Fort Benning by the beginning of fiscal year 2014.
The U.S. Army Armament Research, Development and Engineering Center began development of
a 40 mm airburst fuse in 2011 to improve the ability of grenade launchers like the M320
to engage targets in defilade. Called Small Arms Grenade Munitions, it doubles the lethality
of the standard M433 grenade round by making a small "smart" fuse sensor so that the round
detonates in the air to hit targets in cover or behind obstacles. The airburst function
is similar to the XM25 CDTE which has an onboard laser system to determine the distance to
the target, but SAGM is considered complementary to the XM25 rather than competing against
it, as the XM25 provides direct fire while the M320 fires indirectly. Engineers integrated
sensors and logic devices to scan and filter the environment and then autonomously airburst
the fuse without needing to be told to by the firer. SAGM enables soldiers to accurately
incapacitate personnel targets in defilade at ranges between 50 to 500 meters. The round
is engineered with three firing modes of airburst, point detonation, and self-destruct. A successful
demonstration occurred in November 2013, with first issuing to soldiers planned by July
2015. See also
KAC Masterkey M26 Modular Accessory Shotgun System
Rifle grenade Under-slung Grenade Launcher
Related Lists: List of individual weapons of the U.S. Armed
Forces List of crew served weapons of the US Armed
Forces United States 40 mm grenades
References
This article incorporates public domain material from websites or documents of the
United States Army. External links
XM320 40 mm Grenade Launcher Module Fact sheet AG36 / AG-C / EGLM / XM320 grenade launcher
page on Modern Firearms site M320 on GlobalSecurity.org
XM320 page on HK USA site