Heckler & Koch XM8
Heckler & Koch · Assault Rifle · Discontinued · 2003
Also known as: XM8, Lightweight Modular Weapon System, LMWS
Overview
The Heckler & Koch XM8 is a select-fire assault rifle chambered in 5.56x45mm NATO, produced by Heckler & Koch GmbH since 2003.
Specifications
| Weight (empty) | 3400 g (119.9 oz) |
| Overall Length | 838 mm (32.99") |
| Barrel Length | 318 mm (12.52") |
| Action Type | Gas Operated Short Stroke |
| Firing Mechanism | Hammer Fired |
| Trigger Type | Single Stage |
| Magazine Capacity | 30 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 900 m/s (2953 fps) |
| Muzzle Energy | 1620 J (1195 ft·lbf) |
| Effective Range | 500 m (547 yd) |
| Rate of Fire | 750 rpm |
| Barrel Rifling | Right Hand |
| Rifling Twist | 178 mm (7.01") |
| Number of Grooves | 6 |
| Frame Material | Polymer |
| Barrel Material | Steel |
| Stock Material | Polymer |
| Finish | Flat Dark Earth |
Calibers
- 5.56x45mm NATO · primary · 5.56mm NATO — also known as 5.56x45mm, 5.56 NATO
Features
- Firing modes: Semi Automatic, Burst 3, Full Automatic
- Feed systems: Detachable Box Magazine, Drum Magazine
- Safety mechanisms: Ambidextrous Safety Selector, Fire Selector
- Features: Rotating Bolt, Gas Operated Short Stroke Piston, Modular Barrel System, Quick Change Barrel, Integrated Reflex Sight, Select Fire, Polymer Construction, Picatinny Rail, Folding Stock, Xm320 Grenade Launcher Compatible, Reduced Fouling Gas System
Variants
- XM8 Compact Carbine — Compact
- XM8 Sharpshooter — Designated Marksman
- XM8 Automatic Rifle — Squad Automatic
Service history
Operators
- United States Army · as XM8 (evaluation only)
- Malaysian Armed Forces · as XM8 (evaluation only)
Production
Estimated total produced: 200 · Production years: 2003-2005
Approximately 200 prototypes produced for evaluation. First 30 prototypes delivered November 2003, with 170 additional units delivered December 2003 from Oberndorf, Germany.
Origin
Country of origin: Germany
Discontinued: 2005
Notes
The XM8 emerged from the kinetic energy component of the cancelled XM29 OICW program. Its distinctive futuristic appearance earned it the nickname 'the fish gun' among soldiers. The weapon featured a reduced-fouling gas piston system that promised significantly longer maintenance intervals compared to the M16's direct impingement system. In testing at Aberdeen Proving Ground, the XM8 demonstrated substantially fewer stoppages than the M4 carbine. Despite strong technical performance, the program was cancelled after Colt and FN Herstal lobbied Congress, arguing the sole-source contract to HK was unfair. The basic carbine configuration used a 12.5-inch barrel, while the sharpshooter variant used a 20-inch barrel. A 100-round drum magazine was also under development for the SAW variant.
Background
The XM8 is one of the most tantalizing 'what ifs' in modern military procurement. It convincingly outperformed the M4 in reliability testing, yet was killed not by technical shortcomings but by procurement politics. Colt's lobbying campaign and congressional intervention effectively ensured the M4 platform would continue to dominate U.S. military service for decades to come. The XM8's distinctive space-age polymer aesthetic made it a favorite in video games and science fiction long after its cancellation.