XM8
Summary
| Country | 🇩🇪 Germany |
| Category | Assault rifle |
| Manufacturer | Heckler & Koch |
Technical specifications
| XM8 | |
|---|---|
| Fire Rate | 750 rounds/min. |
| Caliber | 5.56 x 45 mm OTAN |
| Magazine | 30 - 100 rounds |
| Length | 838 mm (33.0 in) |
| Weight | 2.6 kg (5.7 lb) |
| Range | 450 m (1476 ft) |
Description
The Heckler & Koch XM8 was a lightweight assault rifle system developed from the late 1990s to early 2000s by Heckler & Koch (H&K). It originated from the rifle module of Alliant Techsystems's XM29 Objective Individual Combat Weapon (OICW) project. When the XM29 encountered issues meeting requirements, the rifle portion was separated, leading to the XM8 program. The U.S. Army considered the XM8 as a potential replacement for the M16 and M4 series, aiming for a weapon that was cheaper, lighter, and more effective.
Prototype testing revealed challenges including battery life for the sight system, ergonomics issues, weapon weight, and heat resistance of the handguard. Funding for large scale testing was denied by Congress in 2004, and the program was put on hold due to technical challenges, funding constraints, and external pressure regarding procurement processes. The Army later issued an RFP for the OICW Increment One family of weapons in 2005, which had similar requirements to the XM8 but included a Squad Automatic Weapon (SAW) configuration requirement. This RFP was put on hold and subsequently cancelled on October 31, 2005, effectively ending the U.S. Army's XM8 program, though it was later included as a candidate in the SCAR competition. Further dust testing in 2007 showed a significantly lower number of stoppages for the XM8 compared to M4 carbines, FN SCAR, and HK416 under test conditions. Engineering work was conducted in the United States and Germany.
The XM8 is a selective-fire 5.56mm assault rifle operating from a closed rotary bolt, based on and sharing design and engineering with the Heckler & Koch G36 rifle. The construction utilizes almost entirely composite materials, except for the cold-hammer-forged steel barrel. The weapon featured an integrated optical sight and IR laser aiming module/illuminator, intended to consolidate functionality found in separate accessories on previous firearms. The XM8 initially used PCAP (Picatinny Combat Attachment Points) for accessory attachment instead of the standard Picatinny rail, though some variants had MIL-STD-1913 rails. PCAP aimed for more precise accessory connection but required adapters for legacy Picatinny attachments. Controls were completely ambidextrous. A potential electronic round counter system was also proposed. The XM8 was chambered for 5.56×45mm NATO, utilizing a 30-round plastic box magazine shared with the G36, which required an adapter for compatibility with M4/M16 metal STANAG magazines.
Throughout its development, the XM8 was conceived as a modular system with several proposed variants achievable by reconfiguring parts. These included:
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A compact personal defense weapon (PDW) with a 241 mm (9.5 in) barrel
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A carbine with a 317 mm (12.5 in) barrel (also depicted with an XM320 grenade launcher)
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An automatic rifle variant with a 508 mm (20 in) barrel
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A designated marksman rifle with a 508 mm (20 in) barrel, integrated folding bipod, and a higher magnification scope
A Light machine gun variant with a heavy 508 mm (20 in) barrel, integrated bipod, and support for a 100-round dual drum Beta C-Mag was also proposed. Modularity was intended to allow quick repairs, barrel length changes, and potentially caliber changes in the field.
Although the U.S. Armed Forces ultimately did not adopt the XM8, Heckler & Koch marketed the system internationally. By 2007, the Malaysian Armed Forces expressed interest, and the Royal Malaysian Navy special unit PASKAL began using the XM8 by 2010.