THE GUN THAT NEVER WAS: Heckler & Koch G11

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It had it all -- accuracy, ease of use, and a revolutionary "caseless ammunition" system that might have changed the way rifles are made -- but the Heckler & Koch G11 rifle was never put into mass production. What happened to this unique rifle?



Some of the most interesting innovations in military technology are never implemented -- not because the innovation was a bad idea to start with, or due to design flaws, but simply due to bad timing. Case in point: the revolutionary Heckler & Koch G11, a rifle that used unprecedented "caseless ammunition," as well as advanced aiming and recoil-less firing capabilities. Its only sin? It was ready for action in a period of political unification and cost-cutting measures.

Blaze of Glory: Improving Burst Accuracy

The short, bittersweet tale of the G11 began in 1970, when the then-West German government initiated a study to produce a new combat rifle to replace the 7.62mm G3 battle rifle currently in service. Among the many requirements for the rifle were that it carry 50 rounds of ammunition (to reduce magazine changes), have a flat trajectory through 300 meters (to facilitate rapid aiming), have a high degree of accuracy when firing 3 round bursts (for improved lethality), and weigh less than 10 pounds with 100 rounds of ammunition.

Of these requirements, the most challenging to overcome, and what made the G11 such a revolutionary weapon, was the issue of burst accuracy. Following a 1960s study at Frankfurt's Battelle Institute, it was determined that current methods of automatic and burst fire management were not capable of meeting the accuracy demands established by the German government. Fully automatic fire generates individual recoil impulses which not only causes the rifle to rise (as the weapon pivots on the firer's shoulder), but when transferred to the shooter's body, these impulses cause the shooter's torso to rotate as well. As a result subsequent shots will be high and wide compared to the first, meaning that if the first round missed the target, all subsequent rounds would also miss the target.

The study concluded that there were two solutions to this problem. The first was the "shotgun" approach, in which a large number of projectiles would be launched at the same time, saturating the target area. This option was rejected because the size of the shell needed to launch a sufficient number of projectiles would have not only reduced the overall combat load of the firer, but the high recoil impulse generated with each shot would have had a dramatic effect on subsequent shot times and accuracy. Accordingly, the second option, in which "salvos" of bullets were fired at as high a speed as possible, so as to reduce the effects of recoil on bullet accuracy, was the one recommended.

In order to condense individual recoil impulses into one manageable force however, required the weapon have a cyclic rate of fire of 2,000 rounds per minute, which was not achievable utilizing conventional single barrel technology. To meet this requirement Heckler & Koch, the manufacturer selected to build the G11, eliminated the cartridge case extraction and ejection steps from the firing cycle and turned to the Dynamit Nobel company to develop a new type of bullet technology: caseless ammunition.



The GL11 rifle with an optical scope mounted.

The Revolution

H&K's caseless ammunition concept was revolutionary for a number of reasons. First, and most importantly, by eliminating two steps from the seven-step firing cycle (see box on right), the cyclic rate of fire could be increased to meet design requirements. Second, since there is no brass (casings left over from firing a weapon) to eject, there is no need for an ejection port, which means the rifle's action is protected from external fouling and contamination. Finally, eliminating the bullet case not only reduces the overall weight of the bullet, but also allows for a more efficient design to be used.

To overcome the numerous technical obstacles associated with such a new and radical weapon design, H&K and Dynamit Nobel, along with optics manufacturer Hensoldt/Wetzlar, combined their development efforts to form the GSHG (Gesellschaft für Hülsenlose Gewehrsysteme, or Corporation for Caseless Rifle Systems).

The most challenging of these obstacles was the development of the caseless ammunition itself. Early tests with molded gunpowder led to the development of High Ignition Temperature Propellant (HITP), a less sensitive compound that would reduce the risk of "cook offs" where the internal chamber temperature was high enough to ignite the propellant. The propellant is molded into a rectangular block around the 4.7mm diameter projectile and cartridge primer. The rectangular shape allows the rounds to feed more efficiently from the magazine -- since there is no magazine "dead space," as there would be with conventional round metallic cartridges, there is no room in the magazine for the bullets to shift and potentially mis-feed. In addition to improving feeding, the molded propellant also significantly reduces the weight of each individual cartridge (A G11 rifle, with 45 round magazines and 510 rounds of 4.7mm caseless ammunition, weighs as much as a G3 rifle with 20 round magazines and 100 rounds of 7.62mm ammunition).

The rifle itself is relatively straightforward (the G11 fires from the "closed bolt" position, and the breech is gas piston operated), with the exception of the rotating breech/chamber cylinder. With no bullet case to extract, there is no need for a locking bolt/chamber arrangement, as there is in conventional rifles. In its place, the G11 has a rotating cylinder that serves as both breech and firing chamber. Rounds are fed vertically through the top of the weapon (the feed magazine and two spares are mounted horizontally over the long axis of the barrel housing) into the cylinder breech, which is then rotated 90 degrees to align the chamber with the barrel. When fired, the gas piston rotates the cylinder back 90 degrees and another round is loaded.


Schematic of G11 bolt and feeding system.

The rifle itself is relatively straightforward (the G11 fires from the "closed bolt" position, and the breech is gas piston operated), with the exception of the rotating breech/chamber cylinder. With no bullet case to extract, there is no need for a locking bolt/chamber arrangement, as there is in conventional rifles. In its place, the G11 has a rotating cylinder that serves as both breech and firing chamber. Rounds are fed vertically through the top of the weapon (the feed magazine and two spares are mounted horizontally over the long axis of the barrel housing) into the cylinder breech, which is then rotated 90 degrees to align the chamber with the barrel. When fired, the gas piston rotates the cylinder back 90 degrees and another round is loaded.


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To achieve the desired degree of accuracy in burst mode, the G11 relies on an extremely high (2,000 rpm) rate of fire. At this speed, 3 rounds can be fired in 60 milliseconds, which means the projectiles have already cleared the barrel before the recoil forces have had a chance to affect the shooter's aim. In comparison, on full auto the G11 has a cyclic ROF of only 460 rpm, with one bullet fired every 130 milliseconds. The final production model, the G11K2, was equipped with a bayonet/bipod mount under the barrel and a 1x large eye relief aiming scope featuring an illuminated aiming circle (though this may be removed and replaced with any existing combat optic or night vision device).

End of the Story?

In 1989, after extensive field-testing with the Bundeswehr (German Army), the final version, the G11K2, entered production and delivery to the Bundeswehr commenced in 1990. The K2 version of the G11 featured several advantages over previous prototypes: Most notably, the receiver was redesigned so that three 45-round magazines could be carried side by side on the rifle. This enabled the soldier, with a total weight of less than ten pounds, to carry 135 magazine-loaded rounds right on the rifle. During testing of the G11 K2 in the Fall of 1989, German Army draftees achieved an average of 50% more hits using the G11 compared with the G3 rifle. Other tests in 1990 showed that of 60,000 rounds fired by a G11, the estimated ammunition failure rate was about 1/485 rounds, with a minimum cook-off rate of 150 rounds at 60 RPM. In early 1990 the German Army issued an official statement on the testing program, in which the rifle was said to have met all requirements, and was ready to be fielded.

But the G11 was never adopted by the German Army to replace the G3. Though no specific reason was given, the likely culprit was simply the changing times: the demise of the Soviet Union, the collapse of the Warsaw Pact and the reunification of Germany. The German Parliament may have decided to reallocate the G11 funding to support reunification programs, or perhaps the German government decided to go with NATO's request to adopt a rifle which fired the then-NATO standard rifle cartridge, the 5.56x45mm. Whatever the reason, the G11 remains shelved, while the G3 was ultimately replaced by the 5.56mm firing H&K G36 in 1999.

The story doesn't quite end there -- here in the US, there have also been recent tests of the G11 technology. A third prototype, the HK-ACR (Advanced Combat Rifle) was tested in 1990 at Fort Benning, Georgia. The HK-ACR was identical to the G11 with the exception of an optical sight designed for targets ranging from 25 to 600 meters. The rifle reportedly received high marks and there were no major parts failures experienced on any of the fifteen test weapons used. While there have been no recent reports about caseless ammunition technology, there may come a time when the G11's innovations are included with future rifle upgrades, here in the US or elsewhere. As long as the technology is out there, the G11 story may have a happy ending after all.


The 7-Step Firing Cycle


The seven steps in a firing cycle are as follows:

1. Firing.
2. Unlocking the bolt.
3. Extracting the spent cartridge case.
4. Ejecting the spent case.
5. Feeding a new cartridge from the magazine.
6. Chambering the round.
7. Locking the bolt.

The G11, with no case to extract or eject, omits 3 and 4 (and because it really doesn't have a recoiling bolt in the traditional sense, steps 2 and 7 are abreviated).

Weapons either fire from the open (i.e. empty chamber) bolt position, or the closed bolt (loaded chamber) position. The M-16 is a closed bolt weapon, while the M240 machine gun is an open bolt weapon. Weapons that fire from the closed bolt start on sequence number 1 and go down through 7. Weapons that fire from the open bolt start on sequence number 5 and work their way down through 7 back to 1, and finally stop on 4 (with the bolt locked open).



G11 Specifications

Caliber:
4.73 x 33 mm caseless ammunition


Builder:
Heckler & Koch


Weight:
3.8 kgs


Overall Length:
750 mm


Barrel Length:
540 mm


Sights:
Optical; special sights like night vision optional


Function:
gas-operated, rotating breech, select-fire rifle (semi-automatic, full-auto fire)


Firing Cycle:
600 rpm for sustained fire;
2000 rpm for 3-round burst



Muzzle Velocity:
3930 m/s


Magazine Capacity:
45 rounds (3 magazines are directly attached to the rifle)


Maximum Effective Range:
400 m


Ellie