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M320 Grenade Launcher Module (GLM)

The M320 40mm grenade launcher is an interoperable system, attaching under the barrel of the rifle or carbine and can convert to a stand-alone weapon. The M320 is designed for attachment to the M16A4 rifle, while the M320A1 is designed for attachment to the M4 carbine. Both weapons are generally referred to only as the M320 and the basic weapon can also be used in a stand alone configuration, which includes a collapsible buttstock. The M320 improves on existing grenade launchers with an integral day/night sighting system and improved safety features. It also has a side-loading unrestricted breech that allows the system to fire longer 40mm low-velocity projectiles (NATO standard and non-standard).

The weapon's sighting system allows soldiers to target enemies accurately in daytime or nighttime, and reduces aiming error while increasing first-round hit probability. A ranging day/night sight produced by Insight Technology, Inc. of Londonderry New Hampshire provides a high probability of 24-hour first round target engagements within 5 meters out to 350 meters. A mechanical ladder sight can also be used in combination on the M320 launcher. Located on the side of the launcher, the sighting system design lessens interference with rifle and carbine sights, reduces attaching operations to one action, and eliminates the need to re-zero after reattaching to a weapon. The sights for the M320 are attached directly to the grenade launcher's receiver ensuring the zero (aiming/impact point) of the weapon is retained when it is removed and later reinstalled on another weapon or when its used in the stand-alone mode. The building block design approach of the M320 allows for a choice of three distinct sighting systems.

The M320 is more reliable and safer because it uses a more modern double-action trigger/firing system. If the weapon misfires, the operator can pull the trigger again, compared with the M203, which requires cycling of the breech to re-cock the firing pin and pulling the trigger again. The new pistol grip design eliminates the need to use the magazine as a hand grip. The latest in lightweight material composites are used to improve durability.

The M320 Grenade Launcher Module (GLM) is a derivative of the German-made Heckler and Koch AG36. Development of what was first designated XM320 began as part of the Objective Individual Combat Weapon's (OICW) Increment 1, the development of a 5.56mm Modular Assault Weapons System, derived from the so-called kinetic energy (KE) component of the orginial OICW design. The first versions of the Grenade Launcher Module were intended to be attached to the XM8 Lightweight Carbine and were more visually similar to the original AG36. Later versions differed more from the original design, and Heckler and Koch subsequently marketed the variant as the AG-C.

The XM320, a 40mm low-velocity grenade launcher, was intended to replace selected M203 series grenade launchers mounted on the M16/M4 series of rifles and carbines as a separable under-barrel module. It would also provide the grenade launching capability for the OICW's Increment I system, based on the XM8 Lightweight Carbine. The XM320 40mm grenade launcher could also be used in a stand alone mode when the add-on, multi-position sliding buttstock was added.

The system was to be fitted with an integral day/night sighting system that provided accurate grenade fires out to the maximum effective range of fielded ammunition. The open-architecture attachment system enabled mounting on M16A2, M16A4, M4, and OICW Increment I rifles and carbines. The unrestricted breech mechanism allowed the use of longer ammunition than was then fielded, ensuring a degree of system growth. It was lighter, safer, and more reliable than the M203 through the use of lighter materials and a more modern trigger/firing system.

In September 2004, the US Army Research and Development Command (ARDEC) at Picatinny Arsenal, New Jersey, announced a requirement, first posted on 26 April 2004, for a 40mm Grenade Launcher Module (GLM) as an approved Soldier Enhancement Program system item. The Request for Proposals was solicitation number W15QKN-04-R-0425. Soldier Enhancement Program systems required a Commercial Off the Shelf(COTS)/Non-Developmental Item (NDI) solution. The system had to be ready to use or require only minimal modification (expected modifications were sight and rifle/carbine integration). The GLM would replace the M203 Grenade Launcher as a lethality upgrade in the emerging US Army "Units of Action" and it would also be fielded within the Army's Training and Doctrine Command (TRADOC).

The GLM was required to be more reliable, more ergonomic, more accurate and safer than the M203 Grenade Launcher. The GLM would be capable of firing all existing US standard 40x46mm low-velocity ammunition. It had to have a breach mechanism that was able to accept improved lethality munitions with longer payloads/projectiles than existing 40x46mm munitions to accommodate system growth. The GLM had to initially mount on the M4 Modular Weapon System (MWS) with a mounting architecture flexible enough for adaptation to the M16A2 and M16A4 rifle, as well as future rifles/carbines. The mounting hardware could differ for each host weapon. However, the basic launcher and sighting system had to be able to mount to all host weapon variations with only minor modifications. When removed and replaced, the module would return to its normal bore alignment regardless of the host weapon interface.

The GLM had to have a probability of hit (within a 5 meter radius) of: greater than 60 percent at 100 meters, greater than 50 percent at 200 meters, greater than 30 percent at 300 meters, and greater than 20 percent at 400 meters. The GLM would include a sight that provided day and night targeting and a secondary sight in the event the primary sight might become inoperable separated from the weapon. The GLM system had to have a range determination capability. Each GLM would possess a stand-alone capability in addition to its role as a combination weapon.

The GLM requirement would be met with a base contract of 60 systems for developmental testing to be procured in FY05. The contract would also contain 2 options. The first option would contain quantities for 500 to 2000 systems and the second option would have quantities of up to 9,000 systems. The contractor had to be able to sustain a delivery schedule of 350 systems per month with a possible increase of as much as 1,000 systems per month beginning 60 days from successful completion of First Article Testing. The offeror would submit 4 bid samples, in addition to written technical proposals, at least 2 had to have a day/night sighting system and a range determination device. All 4 would have an M4 MWS mounting configuration, a manual sight, and a stand-alone kit. The winning offeror had to be able to deliver 10 of the 60 systems NLT 30 days from the date of award for safety certification/developmental testing. There would also be a First Article Test quantity of 5 items that must be passed prior to approval of the first option.

On 12 May 2005, Heckler and Koch Defense, Inc. was awarded a competitive contract to produce the new add-on grenade launcher for the US Army. This award marked the completion of a full and open competition among several companies to provide a commercial off-the-shelf (COTS) shoulder-fired grenade launcher that met or surpassed all user-developed requirements. The total potential value of the contract was $29 million with a potential purchase of more than 11,000 launchers, day/night sights, and assorted items (tools, parts, and accessories) over the life of the contract. The XM320 Grenade Launcher Module (GLM) was selected after months of rigorous bid sample testing, including a user evaluation at the Army's Aberdeen Test Center in Aberdeen, Maryland. The open architecture of the XM320 would enable soldiers to easily attach the launcher, in seconds and without tools, to existing and newly emerging weapon platforms ranging from compact carbines to light machine guns.

Heckler and Koch Defense, Inc. of Sterling, Virginia was the US affiliate of Heckler and Koch, GmbH of Oberndorf, Germany. Heckler and Koch Defense supplied the US military and federal law enforcement agencies with technologically advanced firearms, logistical support, training, and specialized design services. Parent company Heckler and Koch was the firm behind some of the most of well known firearms of the preceeding 50 years including the G3 rifle, MP5 submachine gun, USP pistol, and newer models such as the G36 weapon system, the UMP submachine gun, the MP7A1 personal defense weapon, and the HK416 enhanced carbine. The XM320 was a combat-proven design produced by Heckler and Koch based on lessons learned from producing more than 30,000 similar launchers that have been in service since 2000 with the military forces of Britain, the Netherlands, Spain, Germany, and Portugal.

During US Army testing, the robust Heckler and Koch Grenade Launcher Module received superior marks for accuracy, reliability, and modularity. The XM320 Grenade Launcher Module provided unmatched performance and combat capability for the US warfighter, permitting the destruction of point targets and the suppression of area targets under both day and night conditions. As of 2005, plans called for the first Army deliveries to begin in early 2006.

US Army units had begun receiving the M320 in 2009. As of May 2010, testing was being conducted to reduce the size and weight of the Day/Night Sight. Heckler and Koch Defense, Inc. of Ashburn, Virginia, was awarded on 19 May 2010, a $13,700,000 firm-fixed-price contract for the acquisition of 5,400 M320A1 grenade launchers and 600 M320 grenade launchers. Work was to be performed in Oberndorf, Germany (50 percent), Columbus, Georgia (30 percent), and Ashburn, Virginia (20 percent), with an estimated completion date of 31 March 2011. One bid was solicited with one bid received. TACOM, Warren, CCTA-ASA, A, Warren, Michigan was the contracting activity (W56HZV-10-C-0025).

As issued, the M320 came equipped with a sling to carry it when not mounted to the M4 carbine or M16 rifle, which was subsequently reported to be a common method of using the weapon. The sling was a single-point design, that did not adequately restrain or protect the weapon, which could lead potentially to serious damage. Product Manager Soldier Clothing and Individual Equipment (PM SCIE) at the Natick Soldier Systems Center subsequently began the the M320 Grenade Launcher Holster Soldier Enhancement Program to develop a protective holster for the weapon when it was not attached to a host weapon. The SEP allowed the purchase of enough holsters to equip a brigade combat team. Holsters from 3 vendors were tested. One model included pockets for grenades, but was bulky. Another was more streamlined, but offers less protection for the weapon. The third was a cross between the other 2. These holsters were sent to the 75th Ranger Regiment where they were subjected to a set of standardized tests in mid-May 2013. The soldiers filled out surveys after the testing. By July 2013, soldiers of the 10th Mountain Division; the 86th Infantry Brigade Combat Team, Vermont National Guard; and soldiers in Afghanistan were evaluating the holsters. The Consumer Research Team at the Natick Soldier Research, Development and Engineering Center would then collect the data from those evaluations. PM SCIE officials could then make a recommendation to the Maneuver Center of Excellence at Fort Benning, which was expected by the beginning of fiscal year 2014.

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Page last modified: 26-07-2013 11:58:24 ZULU