XM8 rifle

XM8
An early version of the XM8
Type	Assault rifle Automatic rifle Light machine gun Sniper rifle/Designated marksman rifle Personal defense weapon
Place of origin	Germany United States
Service history
In service	2010–present
Used by	Royal Malaysian Navy
Production history
Designed	2002
Manufacturer	Heckler & Koch Alliant Technosystems
Produced	2003–2005 (prototypes only)
Variants	See variants
Specifications
Weight	7.5 lb (3.4 kg)
Length	33 in (838 mm)
Barrel length	12.5 inches (318 mm)
Cartridge	5.56×45mm NATO
Action	Gas-operated, rotating bolt
Rate of fire	750 rounds/min
Muzzle velocity	approx. 900 m/s (see variants)
Feed system	30-round detachable box magazine, 100-round C-Mag drum magazine
Sights	Unmagnified reflex sight (4x for DMR variant)

The XM8 was the military designation for a lightweight assault rifle system from the late 1990s to early 2000s. The rifle was designed by German small arms manufacturer Heckler & Koch (H&K), and shares design and engineering with their G36 rifle.

The XM8 design was originally part of the Objective Individual Combat Weapon program (OICW), which was developing a "smart" grenade launcher system with an underslung carbine rifle. The system was unable to meet performance and weight requirements and was eventually canceled. In the aftermath, the two portions of the OICW were separated, resulting in the XM8 and XM25 projects.

Although there were high hopes that the XM8 would become the United States Army's new standard infantry rifle, the project was put on hold in April 2005, and was formally canceled on October 31, 2005. However, the weapon is now in service with Royal Malaysian Navy special forces and some private military companies.

The U.S. Army's purpose in contracting for this prototype weapon was to provide replacement options for the M16 rifle after the XM29 program ran into problems. The goal was a weapon that was cheaper, lighter, and more effective than the M16 and M4 Carbine series of weapons. The XM8 was not just one weapon but a system which could be reconfigured with appropriate parts to be any one of several variants from a short-barreled personal defense weapon to a bipod-equipped support weapon. It also included an integrated optical sight and IR laser aiming module/illuminator.

The XM8 was based on the rifle module of Alliant Techsystems's XM29 OICW project, of which the weapon mechanisms were the responsibility of H&K. Following the indefinite delay of the Objective Individual Combat Weapon program, the U.S. Army requested that the contractors design stand-alone weapons from the XM29's kinetic energy and high explosive modules.