Skip to content


The XM8 rifle is currently in testing to determine if it will replace the venerable M-16 as the standard rifle of the United States Armed Forces.

There are three variants of the XM8: a compact version with a collapsible stock and a 9.5-inch barrel, a baseline version with a 12.5 inch barrel and a designated marksman version with a 20-inch barrel.

A longer barrel provides greater accuracy over longer ranges. Shorter barrels make the rifles lighter and easier to use in confined spaces.

The 12.5-inch carbine version of the XM8 weighs 6.4 pounds and is 33 inches long with its adjustable stock extended. The M-16 A2 weighs 8.79 pounds with a 30-round magazine and is 39.63 inches long.

In addition to being lighter than the M16 series rifles, the XM8 is designed to be easier to maintain with significantly lower stoppages caused by mechanical malfunction.

In initial U.S. Army testing, the XM8 tested fired 15,000 rounds without cleaning or lubrication without a misfire.

The XM8 rifle is being designed and manufactured by H&K (Heckler & Koch) of Germany.

XM8 Operation

The XM8 uses a rotary locking bolt system that functions and fieldstrips similar to those used in the M-16 rifle. The bolt is powered by a gas operating system with a user-removable gas piston and pusher rod to operate the mechanism.

Unlike the current M-16 direct gas system, the XM8 gas system does not introduce propellant gases and carbon back into the rifle’s receiver during firing.

XM8 Highlights

  • Multi-functional one weapon, many variants
  • Integrated Sight/Lasers
  • Ambidextrous Controls
  • Reconfigurable at unit level – one platform for all variants
  • Backup Mechanical Sight
  • Greater Accuracy – less than 2 MOA
  • Greater Reliability 3X increase >20,000 rounds without stoppages
  • Longer Weapon Service Lifei, 2-3X increase – 20,000 rounds minimum barrel life
  • Reduced Cleaning Time – 70% reduction
  • Reduced Training Time – 2X reduction
  • Lower System Weight – 15% reduction
  • Lower System Cost – 30% reduction
  • Zero Drain Time

XM8 Specifications

Operating System Short stroke piston, gas operated. Firing from a closed bolt. Rotary locking 6-lug bolt head Modes of Fire Semi-auto and full automatic fire (cyclic rate of fire approximately 825 rounds/minute) Magazine 10 or 30 round capacity, 100 round drum also available (30 round magazines can be nested together with or without accessory dual magazine clamp).
Sighting System XM8 Carbine and XM8 Compact Carbine: 1/1 Integrated Sight Module (ISM) with red dot reflex sight adjustable for windage and elevation with IR laser illuminator and pointer. Flip-up mechanical back up sights.
XM8 Designated Marksman/Automatic Rifle (DMAR): 4X Advanced Magnified Optic (AMO) with red dot, etched ranging reticle sight with IR laser illuminator and pointer, adjustable for windage and elevation. Flip-up mechanical back up sights.

XM8 Dimensions

Overall Length Carbine: 30.30 in (buttstock retracted), 33.30 in (buttstock extended)
Compact Carbine: 22.4 in (buttstock retracted), 30.00 in (buttstock extended)
Compact Carbine with buttcap: 21.10 in
DMAR: 37.60 in (butt stock retracted), 40.60 in (buttstock extended)
Height 11.25 inches
Width 2.25 inches
Barrel Length Compact Carbine: 9 inches
Carbine: 12.5 inches
DMAR: 20 inches
Rifling 1 turn in 7 inches
Barrel Life > 20,000 rounds
Stock Collapsible, 5 position adjustable for length, optional retractable buttstock, folding collapsible, and buttcap also available.

XM8 Weights

Compact Carbine 7.10 lb (with collapsible stock)
Carbine 7.51 lb
DMAR 10.18 lb
Sling .485 lb
Magazine (with 30 rounds) 1.08 lb
Empty Magazine .30 lb
Magazine (with 100 rounds) 4.80 lb
Empty 100 Round Magazine 2.20 lb

XM8 Ballistic Performance

Muzzle Velocity (M855 Ball) 9 inch barrel: 2,425fps
12.5 inch barrel: 2,695fps
20 inch barrel: 3,0005fps

Articles on the XM8

Live fire compares M-4, XM8

More than 400 spectators filled the bleachers at Red Cloud Range Sept. 22 to watch a side-by-side demonstration of modern rifle technology. The demonstration was designed to showcase the capabilities of the XM8 weapon system in a comparison with its counterpart, the M-4 carbine.

XM8 Lightweight Modular Weapon 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 Weapon 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 conjunction with the US Army Infantry Center, the XM8 Future Combat Rifle is intended to replace existing select 5.56x45mm weapons in the US Army arsenal.