THE XM8 SYSTEM

Beginning life as the 5.56mm KE (kinetic energy) component of the 20mm air-bursting XM29 Objective Individual Combat Weapon (OICW), the XM8
Lightweight Modular Carbine System represents the state-of-the-art in 5.56x45mm NATO assault rifles. Developed by the US Army’s office of Project Manager for Soldier Weapons located at Picatinny Arsenal, New Jersey in close conjunction with the US Army Infantry Center, the XM8 Future Combat Rifle is intended to replace existing M4 Carbines and select 5.56mm x45 weapons in the US Army arsenal beginning as early as the fourth quarter of FY05. Once adopted, the M8 Carbine will replace the aging M16/M4 family of weapons, which have been in service for nearly four decades, longer than any previous US service rifle. The M8 Carbine will be up to 20% lighter than a comparably equipped M4 Carbine MWS and yet offer additional features and performance unavailable currently in any assault rifle in the world.

As a direct development of the separable OICW (XM29) KE or Kinetic Energy module, the M8 Carbine will share a high degree of common parts and training and maintenance procedures to lessen the required support for the “family” of XM8 weapons. Being developed are four XM8 variants, which include a
baseline carbine, a sharpshooter variant, an automatic rifle variant, and the ultra-compact carbine variant. A unique feature of the XM8 modular weapon system is the ability to easily and quickly reconfigure the weapon from one variant to the other to meet changing mission requirements, to include caliber conversion.

This modularity includes the exchange of interchangeable assembly groups such as the barrel, handguard, lower receiver, buttstock modules and
sighting system with removable carrying handle. In addition and in parallel, the new XM320 quick detachable single-shot 40mm grenade launcher with
side-opening breech and LSS lightweight 12 gauge shotgun module can be easily added to the XM8 by the user in the field without tools. The unique buttstock system allows the operator exchange buttstocks without tools from the standard collapsible multi-position version, to an optional buttcap for maximum portability or an optional folding or sniper buttstock with adjustable cheekpiece for special applications. Internally the XM8 employs a combat-proven robust rotary locking bolt system that functions and fieldstrips like that used in the current M16 rifle and M4 carbine. However this bolt is powered by a unique gas operating system that employs a user removable gas piston and pusher rod to operate the mechanism. Unlike the current M4/M16 direct gas system with gas tube, the XM8 gas system does not introduce propellant gases and the associated carbon fouling back into the weapon’s receiver during firing. This greatly increases the reliability of the XM8 while at same time reducing operator cleaning time by as much as 70%. This system also allows the weapon to fire more than 15,000 rounds without lubrication or cleaning in even the worst operational environments. A cold hammer forged barrel will guarantee a minimum of 20,000 rounds service life and ultimate operator safety in the event of an obstructed bore occurrence.

The XM8 has fully ambidextrous operating controls to include a centrally located charging handle that doubles as an ambidextrous forward assist when required, ambidextrous magazine release, bolt catch, safety/selector lever with semi and full automatic modes of fire and release lever for the multiple position collapsible buttstock. The operating controls allow the operator to keep the firing hand on the pistol grip and the weapon in the firing position at all times while the non-firing hand actuates the charging handle and magazine during loading and clearing. Major components of the weapon are produced from high-strength fiber reinforced polymer materials that can be molded in almost any color to include OD green, desert tan, arctic white, urban blue, brown and basic black. Surfaces on the XM8 that interface with the operator are fitted with non-slip materials to increase comfort and operator retention. The XM8 uses 10 or 30-round semi-transparent box magazines and high-reliability 100-round drum magazines for sustained fire applications.

Special integral flush mounted attachment points are located on the handguard and receiver to allow the quick attachment of targeting devices. Unlike MIL-STD-1913 rails, the XM8 attachment points do not add additional weight, bulk and cost to the host weapon, and will accept MIL-STD-1913 adapters to allow for the use of current in-service accessories. The attachment points for the standard multi-function integrated red-dot sight allow multiple mounting positions and insure 100% zero retention even after
the sight is removed and remounted. The battery powered XM8 sight includes the latest technology in a red dot close combat optic, IR laser aimer and laser illuminator with back-up etched reticle with capability exceeding that of the current M68-CCO, AN/PEQ-2 and AN/PAQ-4. This sight will be factory zeroed on the weapon when it is delivered and does not require constant rezeroing in the field like current rail-mounted targeting devices. The XM8 will be fully compatible with future Land Warrior technology and components.

The US XM8 Carbine is being designed at the HK Defense design center in Sterling, Virginia and will be produced and assembled in the United States at the new Heckler & Koch manufacturing plant located in Columbus, Georgia, adjacent to Fort Benning. The unit cost of the XM8 will be less than that of the current M4 Carbine and will guarantee the American war fighter uncompromising performance far exceeding that of current in-service M4 Carbines.