Resurrected Weapons: The HK G-11

We’re going to look at some prototype rifles that never got off the ground. First is the most exotic, the HK G11.

Back in the 80s, the Bundeswehr issued the G3. They hadn’t yet gone over to 5.56mm yet. And they noticed the classic problem of soldier marksmanship: Most soldiers are very poor shots in combat. But what to do about this problem? Automatic fire is hard to control. It can be done with sufficient training, but we’re talking about the average grunt here. A burst of three or so rounds might sound like the ticket, but subsequent shots tend to miss high and right (or left) based on body mechanics and how they interact with recoil. Consistent high right missing isn’t super helpful for getting a higher hit percentage out of a weapon. What if the burst was out of the gun before the recoil impulse got to the shooter? Three superquick rounds. That might give you the spread you’re looking for.

A brief side note: the US Army, with their cool guy M16s noticed a similar problem, and would launch a search for a similar solution, the Advanced Combat Rifle program, based on similar reasoning to the above.

So we want a burst mode that’s super quick. 2,100-rounds-per-minute quick. That’s gonna be tough. And we’re going to want regular rates of automatic fire if we set the selector to full auto. Here comes the complexity. The engineers at HK considered the problem, and decided on an enabling technology: caseless ammo.

Without that pesky case, there’s no extract/eject portion of a normal operating cycle. Less to do means it’s easier to do it all quickly. Yay! Plus, caseless ammo is way lighter than cased ammo. A gain for the logistics geeks. Plus, this would be a SCHV round: 4.73×33 mm1. This worked to to being significantly lighter than M855 5.56. Rough back of the envelope calculations shows that for about the same weight as a G-3 and 100 rounds of 7.62×51 mm, a soldier could carry a G-11 and 500 rounds of ammunition.

Now let’s get back to America. To get adoption, the US Army wanted the ACR rifle to have a 100% higher hit probability than an M16A2. The G-11 was one of the entrants. Plus it had to be durable and reliable, etc.

A few other notes on the G-11, the rifle to fire these tiny caseless rounds. It weighed about 3.6 kg empty, had a Hensholdt unmagnified reflex sight, and a 45 round box magazine. The G-11 had integrated storage for two additional magazines for quicker reloading, sort of like the redi-mag system. It also had a bottom ejection port for ejection of misfires, or administrative clearing. You might imagine the mechanism to handle the 2,100 round per minute hyperburst plus regular full auto would be complicated and it was. And caseless made it worse. But it worked.

For the hyperburst, the barrel, firing chamber, and magazine assembly were all free floated and recoiled together. Picture a modern howitzer, except much smaller. And the nature of the mechanism meant that you’d get the three projectiles out before that recoiling assembly hit the back of the receiver, which is how they avoided transmitting the recoil for a little while.

Reloading was an interesting design too. Cartridges were in a box magazine above the rotating chamber, and were dropped in tail-first and then rotated 90 degrees into firing position. Turning a cocking lever further would dump a cartridge out the bottom if needed.

Now, let’s talk about the problems. You see, the cartridge case, that pesky bit that we deleted to cut weight and simplify the firing cycle, actually gives us a lot. For one, the cartridge case makes it easy to unload the gun. You can pull pretty easily on the rim of a cartridge case. You can’t pull easily on a compressed powder block. And you’ll want to unload it if a round fails to discharge and you need to get rid of it, or if you’re just done at the range and putting your weapon back.

The cartridge also protects all of your propellant. A cartridge case is relatively durable, and is insensitive to scratches and nicks that might arise from rough handling. It is also reasonably water resistant. No such luck for the caseless round. There were problems with damaged cases and extraction was a pain.

Further, the mechanism got weird because there’s no case to provide a seal at the back of the chamber where the firing pin is, or to seal off the barrel behind the fired bullet. Enter more complexity and a little plastic bit that went at the end of the caseless round to seal the barrel. Barrel sealing problems persisted, though.

Less obviously, the cartridge also provides a great way of getting rid of heat. A bunch of heat from firing the gun goes into heating the cartridge, not the chamber, and then the hot spent cartridge is ejected. Goodbye heat! HK had to contract with Dynamit Nobel for some special insensitive propellant that was then lacquered and used that for the rounds.

Lots of engineering and testing got these problems sorted, more or less. And here’s where the story gets vague. Depending on who you ask, there may or may not have been some thing that weren’t quite sorted. But they were sorted to the satisfaction of the Bundeswehr, who was about to adopt the G-11 in 1990, and there are plenty of documents to back that up. But then the cold war ended. Goodbye Soviet Union, goodbye scary threat, hello expensive reunification. And here the Germans decided against the G-11, which would be massively expensive. Remember, you’d have to set up new weapon and ammo production lines, and the ammo production lines would be entirely new methods. It’s not just a different size of brass/steel cased bullets. NATO wasn’t about to retool with the Soviet Union gone. So instead the Germans moved to (finally) adopt 5.56.

As for the ACR project, well, that was really more of an investigation than a serious replacement effort. And even though soldiers liked the compactness,2 reliability, and capability of the G-11, and even though the G-11 exhibited a significantly higher hit probability than the M-16 (or the G-3 for that matter), it did not meet the 100% higher hit probability, and was not adopted.

Where does that leave us, then? Well, it’s time to decide how we rule on this. And the G-11 has an advantage over some of the other weapons we’ll look at in that it’s doing some things that an M-16/SCAR/whatever-5.56-carbine-you-issue-now can’t do. Namely, that fancy hyperburst, and way more ammo for the weight. Plus, since the ammo in question is square, it packs more compactly too. So there’s a logistics win and a weight of fire win. Both of which I really like. Some of the G-11K2 prototypes even were fitted with picatinny rails to mount different optics, so I don’t even have to worry about having that done.

That said, there are some concerns we’d like to put to rest. Since it’s been a while, let’s get a few LRIP guns to make sure the manufacturing process is still good, and do some high round count testing. Plus, I’d like to do some gel tests and intermediate barrier3 tests. Even if that means some projectile design updates to make the terminal effects satisfactory, I can’t forsee any major problems left.

Verdict: Approved for LRIP and phased adoption by the Borgundy War Department Ordnance Procurement Board

1.) Or thereabouts. I’ve seen some variation betwen 4.7-4.9 mm or so.
2.) Despite looking like a space 2×4, troops even liked the ergonomics
3.) Usually sheet metal and tempered glass, i.e. car parts.

4 thoughts on “Resurrected Weapons: The HK G-11

  1. Arathar

    One mistake: Caseless rounds still need an ejection port for the plastic cap and copper booster container!

    Also im really not sure if the spread word at all. shooting 3 bullets at a spread never make a perfect pattern, sometimes there are all one one spot, sometimes on two, sometimes at tree but too close together. In most cases its a waist of bullets. Also when having such a intendet spread, are single rounds even still accurate? If not, also the 3 rounds could go in the wrong place at once…
    Also the kick of 3 rounds at once its quite harsh. In videos you see how it brings offsite in not perfect stances. Ligh recoil singleshots for reajustment are better than such a unreliable tiny spread, with such high recoil everytime.

    But the reduced firerate fullauto is great for closer quarters.
    Also the bullet should maked more aerodynamic, which luckly would later have been possible for this kind of construction.

    I also think it would be a better idea to rather make it polymer cased, it solves a ton of problem and brings a lot of advantages. Besides all that such pressed propellant have bad and unprogressive burning.

    The biggest problem -> the ultracomplicated mechanism. The Steyr ACR as comperasion was insanly simple even more than conventional rifles.

    The biggest problem with the G11 bore to sight height… incredible high. Shooting over cover would be a pain and extremly dangerous. The enemy spots and hit you far more easy. Also giving you more stress = lowering propability of hit…

    Also a square isnt as good as assumed, a flat rectangular shape would be more efficient.
    Besides that screwing the unreliable not really working hyperburst, and use light recoil shots would open the opportunity for having only a short floating space for barrel recoiling and would give a lot more barrel lenght. Because the only big problem of really small caliber rounds are low bore volume…

    Overall an interesting firearm, but as an engineer, ive done dozends of drastic design changes at the G11 but even if its much better than today firearms when fully perfected, it still cant hold up with our main designs than work diffrent.

    1. parvusimperator Post author

      Well, very harsh in comparison to an AR-15 perhaps. I still don’t think it was super bad (though admittedly I haven’t fired one). And who cares after you got the three rounds down range?

      As for height over bore, yes it’s annoying, but it’s something one can work around.

      In both US Army and Bundesewehr testing though, the G-11 provided a notably higher hit probability overall than either the G3 or the M-16. Not enough for 100% improvement like US Army wanted, but definite, noticeable improvement. So it seemed like hyperburst worked well enough for those purposes, and the recoil and height over bore weren’t hugely problematic enough to wreck it. That said, it’s fair that it didn’t totally work as advertised. Does anything? I’d argue it worked well enough, but that’s quite debatable.

      Some dispersion is good, if you posit an evading target downrange that is trying to avoid your fire. Given some dispersion, and a target that is trying to be unpredictable, you can’t know which of the three rounds will hit him (if any), so you can’t really know which ones are ‘wasted’. Besides, rounds that miss can still have positive effects like suppression. In all those studies of ‘soldiers shoot e.g 50,000 rounds on average to kill one enemy combatant’, I wouldn’t say the other 49,999 (or however many miss) are wasted. It’s hard to actually waste fire in combat. Ditto for multiple hits, supposing you don’t get that desired dispersion. Which one killed him? Did you need all of those rounds to kill him? Was one enough? Two? If you watch the bit where Sonny gets whacked in Godfather part 1, that’s clearly a ridiculous amount of overkill, but at what point does it become overkill?

      Also, part of me wonders if you’d need that burst to maximize the effectiveness of small 4.7ish mm rounds that don’t tumble or fragment.

      Now, on the flip side, as you’re probably thinking, this might not be the best idea if there are noncombatants around that you don’t want to be shooting. That and friendly fire are really the only time when I would say there’s a problem with rounds going where you don’t intend. Again, in Bundeswehr/ACR testing, it was deemed more accurate than a G3/M-16. So while your concerns are reasonable, I think they were probably handled by the time the G-11 was approved in the ’90s.

      As for the complexity, yes. It’s a little clockwork nightmare in there. But it was tested by a number of soldiers as part of the evaluation, and they didn’t seem to have undue issues with it. Probably not a perfect test, and I’d have loved to get some proper field tests with it, but I can only work with the data that’s out there. Anyway, soldiers can break anything. The back was relatively sealed. The armorer’s course probably would have sucked, but I’m pretty sure HK thought of that at the time. Alas, I don’t have the G-11 maintenance manuals.

    2. parvusimperator Post author

      One more thing. Do you have any data on the terminal performance of the Steyr ACR’s flechette rounds?

      I’d be concerns about the terminal performance and intermediate barrier penetration performance of flechettes. Well, in the case when I’m not using a cannon round/bomb full of the things.

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