Heckler & Koch G11
Heckler & Koch · Assault Rifle · Prototype · 1990
Also known as: G11, Gewehr 11, G11 K2, HK G11
Overview
The Heckler & Koch G11 is a prototype bullpup assault rifle chambered in 4.73x33mm HK caseless ammunition, developed jointly by Heckler & Koch, Dynamit Nobel, and Hensoldt Wetzlar from the late 1960s through 1990. Intended to replace the G3 in Bundeswehr service, the G11 was the world's first and only fielded caseless-cartridge weapon, using a polymer-encapsulated block of High Ignition Temperature Propellant (HITP) to eliminate the brass case entirely. Its defining feature is a unique rotating breech chamber that accepts each round vertically from a 45-round tube magazine mounted horizontally along the top of the rifle, rotates ninety degrees to align with the barrel, and fires - completely removing the extraction and ejection cycle. In three-round burst mode the internal bolt group recoils as a single floating unit and cycles at a blistering 2,100 rounds per minute, allowing all three projectiles to leave the muzzle before the shooter perceives any recoil, a behaviour Heckler & Koch marketed as the 'hyperburst.' Although the G11 K2 was formally accepted by the German Bundeswehr in 1990, the program was cancelled within weeks due to budget pressures following German reunification. Only prototypes and a small pre-production batch were built, and essentially all surviving examples are held in Heckler & Koch's factory museum.
Specifications
| Weight (empty) | 3600 g (127.0 oz) |
| Weight (loaded) | 4300 g (151.7 oz) |
| Overall Length | 752 mm (29.61") |
| Barrel Length | 540 mm (21.26") |
| Height | 285 mm (11.22") |
| Width | 65 mm (2.56") |
| Action Type | Gas Operated Short Stroke |
| Firing Mechanism | Hammer Fired |
| Trigger Type | Single Stage |
| Magazine Capacity | 45 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 930 m/s (3051 fps) |
| Muzzle Energy | 1405 J (1036 ft·lbf) |
| Effective Range | 300 m (328 yd) |
| Maximum Range | 400 m (437 yd) |
| Rate of Fire | 2100 rpm |
| Barrel Rifling | Right Hand |
| Frame Material | Polymer |
| Barrel Material | Steel |
| Stock Material | Polymer |
| Finish | Matte Black |
Calibers
- 4.73x33mm HK Caseless · primary — also known as 4.73mm Caseless, DM11, 4.73x33mm DM11, 4.7x33mm Caseless
Features
- Firing modes: Semi Automatic, Burst 3, Full Automatic
- Feed systems: Detachable Box Magazine, Horizontal Tube Magazine
- Safety mechanisms: Rotary Fire Selector, Manual Safety, Bolt Carrier Lock
- Features: Bullpup Configuration, Caseless Ammunition, Rotating Breech Chamber, Hyperburst 3 Round Mode, Integrated Optical Sight, Horizontal Top Mounted Magazine, Dual Spare Magazine Storage, No Extraction Cycle, Polymer Housing, Recoil Delayed Burst, Hitp Propellant
Variants
- G11 Prototype — Prototype
- G11 K1 — Prototype
- G11 K2 — Production
- G11 LMG — Light Machine Gun
Service history
Operators
- German Bundeswehr · adopted 1990 · as G11
- United States Army (ACR trials) · as ACR candidate
Production
Estimated total produced: 4,000 · Production years: 1968-1990
Approximately 1,000 prototype units across successive development iterations plus roughly 3,000 G11 K2 pre-production rifles. Program cancelled before large-scale production; most units were returned to Heckler & Koch and never saw combat.
Origin
Country of origin: Germany
Designer: Dieter Ketterer
Discontinued: 1990
Notes
The G11 program consumed decades of Heckler & Koch R&D budget and contributed to the company's 1991 sale to British Aerospace. The rifle entered the US Army's Advanced Combat Rifle (ACR) trials at Aberdeen Proving Ground in 1989-1990, where it demonstrated improved hit probability over the M16A2 but no weapon was ultimately selected. The caseless DM11 cartridge uses a rectangular propellant block in which the 3.25 g bullet is fully embedded, with a booster charge at the base; early caseless rounds suffered from cook-off that the HITP formulation eventually resolved. The horizontal top-mounted magazine feeds rounds nose-down into the rotating chamber and allows two spare magazines to be stored alongside the active one on the rifle itself.
Background
The G11's three-round burst fires so fast (2,100 rpm) that all three bullets leave the muzzle before the shooter feels any recoil - Heckler & Koch called it the 'hyperburst.' Caseless ammunition let a soldier carry roughly three times the rounds of an equivalent weight of 5.56x45mm NATO, and the rotating breech chamber eliminated extraction entirely. The Bundeswehr formally accepted the G11 K2 in 1990 and then cancelled the program within weeks when German reunification drained the procurement budget; HK nearly bankrupted itself on the G11 program, and the remaining rifles live in the company's private museum to this day.