The Long, Convoluted, Unfinished Saga of Heckler & Koch’s Modular HK433 Rifle

By Peter Nealen

The following is some of Heckler & Koch’s PR boilerplate about the company’s HK433 rifle. Of course, you have to expect some degree of self-importance from any manufacturer, maybe especially HK, and they don’t disappoint.

The new compact and modular assault rifle generation

Countless ideas, decades of know-how, and sophisticated solutions tested and proven under the most rigorous conditions worldwide are the foundation of Heckler & Koch’s pioneering weapon technologies. We leave nothing to chance.

The new HK433 is a modular, and compact assault rifle chambered for 5.56 mm x 45, which combines the strengths and outstanding features of the G36 and the HK 416 families of assault rifles – both proven worldwide. It doesn’t matter whether you are right or left-handed or have trained on a G36 / HK 416 weapon system or AR-15 platform: The HK433 is the solution for every scenario imaginable. Maximum functional reliability with intuitive handling combined with maximum modularity, accuracy, and weapon safety – Made in Germany.

Sensational marketing language aside, let’s delve into the gun.

Specifications

The HK433 is a short-stroke piston-operated 5.56mm rifle with a one-piece rigid upper receiver featuring Keymod-derived attachment points on either side of the handguard. The side-folding adjustable buttstock has five positions and an adjustable cheek riser. The controls are ambidextrous — including a non-reciprocating charging handle which can be switched between left and right-handed use without a tool — and it features a modular barrel system that can be swapped out between 11″, 12.5″, 14.5″, 16.5″, 18.9″, and 20″ barrels, without needing an armorer to do it.

Most of the controls appear to be derived from the G36, which the HK433 was designed to replace. It also seems to feed on standard 5.56 STANAG magazines, including HK’s own steel mags.

The trigger group has three settings, Safe, Semi, and Full Auto. The Full Auto rate of fire is 700 rounds per minute, slower than the HK416‘s 850 rounds per minute, making it somewhat more controllable. In addition, the recoil impulse is well-balanced, driving straight back to reduce muzzle rise.

With a short reset, the trigger pull is — reportedly — around 5.3lbs.

HK433 Background

The HK433 was first introduced to the public at Enforce Tac 2017 in Nürnberg, Bavaria. How it came to be developed, however, is a story that started in 2015.

That was when the German Defense Ministry announced they were seeking a replacement for the Bundeswehr’s G36s, primarily because of reports that the rifle lost accuracy after a high volume of fire.

While that was disputed by some, the story is that increased heat softened the polymer upper receiver, making the barrel “float” and altering the zero. The reports were concerning enough that the Bundeswehr decided to seek a replacement.

Heckler & Koch’s immediate go-to was be the HK416, a slightly altered, piston-driven version of the M4 platform. The 416 has seen extensive use throughout the world, including by American special operators. It has been adopted by the US Marine Corps as the M27 IAR in the move to replace the M249 SAW with a lighter automatic rifle. It has also been adopted as the replacement for the FAMAS in the French Armee de Terre and as the new Norwegian service rifle.

However, the Bundeswehr decided the HK416 was too expensive for their requirements, and so, when the competition opened, Heckler & Koch submitted the HK416 and the HK433, the 433 being a somewhat modernized and, more importantly, a cheaper alternative.

The complete list of contenders has never been revealed. Still, the initial bid process resulted in no winner since the Bundeswehr said that none of the contenders met their technical requirements, including a 7.62mm variant for specific units. They then gave the companies eight additional months to fix things.

Competition Controversy

The competition came down to HK433, the 416, and the Haenel Mk556. Haenel is an old German company based in Thuringia and is now owned by a state arms manufacturer in the UAE. The Mk556 is essentially a UAE-built Caracal CAR-816 carbine which, it has also been noted, is itself a low-cost HK416 clone.

The Bundeswehr chose the Haenel. And then all hell broke loose.

Heckler & Koch sued, mainly over the similarities between the Mk556 and the HK416, arguing that Haenel violated their patent. The result has been a cancellation of the contract and the entire replacement program went back to square one, with the G36 remaining in service, apparently indefinitely.

So, where does that leave the HK433?

No one really knows. Heckler & Koch put a significant investment into this weapon system, and they are still marketing it for military, police, and security use.

But will they have any takers? It’s hard to say. They seem to be a little late to the party regarding the HK433’s design.

It may be a fantastic rifle, but it doesn’t do anything that hasn’t already been done by the SCAR-L, which also features a rigid, one-piece upper receiver, or the BREN 2, which the Czechs and Hungarians have adopted. So far, there hasn’t shown a single primary taker for the HK433. Yet.

With the Haenel contract canceled, the Bundeswehr might well decide to adopt the HK433, though that remains to be seen. The political fallout of the contracting debacle is still going on. But if the Bundeswehr thought the HK416 was too expensive, and the much cheaper Mk556 is out, the HK433 might become much more attractive to the Bundeswehr, given its lower price point and, hopefully, better performance than the aging G36.

Attaining access to the HK433

Getting to shoot the HK433 is pretty iffy, given that HK is marketing it solely to the Bundeswehr and other military/police/security agencies now. That’s pretty much par for the Heckler & Koch course and, given their own policies and US import laws, a commercial version of the HK433 is currently nowhere on the horizon. Even if they eventually produce one, it will likely be costly, even without the modular barrel system.

That means that in the short term, the only real chance American civilian shooters will have to play with a 433 isn’t going to be an actual rifle, but either airsoft clones or video game reproductions, such as Call of Duty’s “Kilo 141.” (Strangely, nobody’s modded it for ARMA III yet.)

The Kilo 141 appears to be an HK433, but in keeping with Call of Duty’s deviation from reality, it’s marked in English with “Cal. 5.56mm,” is supposedly from Switzerland, and is built by the fictional “Singuard Arms.” It’s also an anachronism in the game. It appeared in 2019 and 2009, when it was still in the prototype phase during 2019, and still hasn’t been adopted by any military or other government agency.

Alternatives to the HK433

Video games can be fun, but they aren’t nearly the same as handling and shooting the real deal. Again, it’s unlikely that Heckler & Koch will produce this for the commercial market, but there’s still hope. After all, while certain gun snobs will insist that it’s not the same thing (and to some extent, they’re right), Zenith Firearms produces semi-auto MP5 clones, and Tommy Built Tactical has been building G36 clones of late. They’re not cheap, but if you really, really want to get your Teutonic Operator on, it is possible to do so, at least with a variant on the MP5 or G36.

In time, one or another of these companies might well produce a workable HK433 clone that will be close enough to get a feel for the real thing.

Is this the ultimate expression of German engineering?

It’s hard to say, given that the HK433 hasn’t seen service or any kind of widespread use at all. With an aluminum upper receiver, it might well avoid the reported problems of the G36, with a lower price point than the HK416.

Accuracy hasn’t been discussed much, and some of that will depend on the barrel in use. Those who have shot it and written about the experience appear to like it, and the trigger reportedly isn’t bad. Given that HK triggers, in general, aren’t great, that’s saying something.

In the end, though, the HK433 is ultimately a compromised version of the HK416, adding features that have been common for a long time now, between the FN SCAR, the Remington ACR, and the CZ BREN 2. There’s really nothing revolutionary here.

Heckler & Koch may have done it marginally better than FN or CZ (Remington is otherwise involved these days), but considering that the HK433 was designed to be less expensive than the HK416, expecting a new Magic Boomstick out of it is probably unlikely.

Short version: Given HK’s reputation, the HK433 probably a reliable, functional carbine. But only time will tell if it gets adopted by anyone. After all, some flat-range shooting and video game clones are a long way from widespread use in the hands of infantrymen.

Pete Nealen is a former Reconnaissance Marine, a veteran of Iraq* and Afghanistan**, and more than a bit of a Renaissance Man. In addition to a number of online articles for various publications, Nealen has written more than two dozen novels and a pair of non-fiction works. When he’s not penning action books or musing about the Triarii, he can be found…actually, that’s really all he does. Plus the occasional freelance article of course.

*1st Platoon, Bravo Co., 1 Recon Bn.
**4th Platoon, Force Reconnaissance Company, I MEF.

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