The G36 Controversy Intensifies

The recent controversy surrounding the H&K G36 rifle (previous articles regarding on the subject available here, here, here, and here) may come to a head soon. The issue of a new Bundeswehr rifle was brought up recently in the German government. From (machine translated):

Berlin (Reuters) – The future of the G36 as the standard assault rifle of the Bundeswehr is questioned due to technical failures.

“The G36 apparently has a precision problem at high temperatures, but also in the hot shot state,” said Defence Minister Ursula von der Leyen on Monday, citing initial assessments of experts who had examined, built by Heckler & Koch rifle after defect reports. In the coming days Inspector General Volker Wieker will issue a transfer, as the troops could continue to use the weapon and on which Ausrüstungsmix the soldiers should take in use. Once the final report of the expert vorliege, the Ministry will consider further consequences. “This includes the question of whether and to what extent the force must be fitted in the medium term with another assault rifle.”

Inspector General Wieker advised the Stewards of Defence and Budget Committee of the Bundestag and the troops. According to the experts the accuracy inaccuracy in G36 was significantly greater than in the investigated comparison weapons, he told the soldiers. The G36 was thus clearly part of the problem – and not just the ammunition or other factors. The defects were observed with all tested types of ammunition and delivery charges.

The investigations showed so clearly a “capability gap in a given scenario,” said Wieker. The problems träten at high temperatures, but also for hot shot weapons. For a transitional period, the rifle can be used in the opinion of the army but. The temperature problems are particularly severe for the troops, because to a large part of their missions in hot regions like Afghanistan, Mali and the Horn of Africa.Armed Forces patrols in Afghanistan, however, were equipped in the past, not only with the G36, but also with other guns like the older G3 or newer G28.

The Green Verteidigungssexperte Tobias Lindner spoke of a worst-case scenario for the Bundeswehr. “Unlike other weapons systems relate to the problems with the G36 not only individual organizations, but almost all soldiers,” said Lindner. The list of disaster in the defense sector will thus longer a particularly sensitive point. Von der Leyen now must finally put other priorities. “While the Minister likes to talk about European drone programs or a new air defense system, show the problems of clothing and now the standard rifle G36 that there are massive problems in the armed forces in the simplest parts of the basic equipment,” criticized the Green Party.

After some conflicting reports on defects in the G36 had ordered von der Leyen 2014 comprehensive examination of the rifle. The serviceability testing procedure, a committee of experts involved in the experts at the Fraunhofer Institute, the Federal Court and the Federal Armed Forces.”The final report is still pending, but so far available reviews are unequivocal direction,” said von der Leyen. It was good that now subject many facts on the table. “Well, from today’s perspective, that was stopped in close agreement with Parliament in the summer of 2014, all other G36 procurements,” added the CDU politician.

The G36 had the older G3 replaced in the army from 1997 as a standard weapon. According to the German military and the armed forces of Spain, Latvia and Lithuania use the gun for this purpose. The G36-producer Heckler & Koch is highly leveraged and therefore is already under pressure.

Heckler and Koch would not be deterred. They released not one, not two, but three press releases in response:


Given the current situation of numerous undifferentiated negative reports regarding the G 36 assault rifle manufactured by Heckler & Koch, as the result of press statements by the Ministry of Defence and Defence Minister Ursula von der Leyen, we feel obliged to issue the following statement:

Unfortunately, the current statements by the German Armed Forces about the G 36 rifle were first brought to the attention of Heckler & Koch through enquiries from the press. Despite several offers by Heckler & Koch to involve the extensive know-how of the company accumulated over many years, the German Armed Forces have not involved Heckler & Koch in the investigation.

Quite to the contrary, the German Armed Forces have not communicated with Heckler & Koch for nearly six months regarding unsupported allegations regarding accuracy issues with the G 36 at high temperatures. The G 36, is acknowledged worldwide as a, technologically superior assault rifle. Unfortunately the German government did not afford an opportunity for Heckler & Koch to contribute correct information and facts that would have clarified and addressed any issues.

The results being currently disseminated, diametrically contradict the extensive and elaborate testing conducted by Heckler & Koch, in view of emerging rumors regarding the accuracy of the weapon following prolonged firing or due to hot weather conditions, as well as those conducted by the Federal Office for Defence Technology and Procurement (BWB). These investigations have shown no relevant limitations in operational suitability if used correctly, nor are there any significant differences in these conditions in comparison with other assault rifles.

No documents are available to Heckler & Koch regarding the current allegations, so  it is not currently possible to provide an urgently required factual investigation into these reported results. Therefore, Heckler & Koch can only state that the G 36 has consistently met, or exceeded any and all testing requirements specified by the German government, which includes an accuracy test, for all G 36’s delivered over the last 15 years and we have no reason to believe that the G 36 rifle is in any way an unsuitable assault rifle.


Heckler & Koch would like to make the following comments with regard to the current negative reports on the G 36 rifle, in particular with regard to the current press statement by the Minister of Defence:

We have been a reliable partner for the German Armed Forces for more than 50 years. The G 36 has been in use for nearly 20 years and has proven itself in more than 35 countries worldwide in numerous operations. We are dismayed by the statements issued during the past few days by the Ministry of Defence with regard to the G 36 rifle. In particular, we sincerely regret that ministry did not seek discussions with Heckler & Koch prior to the last public statement with far-reaching consequences for our technical reputation.

Heckler & Koch would like to clarify the following points:

1) All G 36 rifles of the German Armed Forces comply with the so-called “Technical Supply Specifications” as established by the German Armed Forces, which conclusively standardize and document the technical performance specifications of the G 36 rifle as part of the supply contract.

2) Our compliance with the stated requirements of these specifications is independently confirmed by the quality control centre of the German Armed Forces with the acceptance of each of the 178,000 G 36 rifles used by the soldiers of the German Armed Forces. To date, there have been no defects noted and therefore, any discussions regarding warranty for defects are neither factual, nor appropriate.

3) Press reports suggest that the German Armed Forces appear to have developed some new test criteria during the past 6 months, without consulting with, or including Heckler & Koch in the discussion of the new testing to be conducted or the results obtained.

4) To date, no office within the German Armed Forces have contacted, or even informed, Heckler & Koch, of any issues where the G 36 has failed to meet its specifications, although the company has offered an open dialog at all times.

5) Over the past few years, individual parties within the German Armed Forces have time and again claimed that new user scenarios had been developed from operations and it is in these scenarios that issues have been observed. Should this be the case, then these altered use scenarios may themselves be creating issues. As there are presently a number of indicators that the use parameters applicable to our product have been changed, arbitrarily, it is suggested that this is the area where a mutual dialog could best serve our forces and allies. Heckler & Koch remains ready and willing to engage in these discussions to resolve once and for all these reports and concerns.

6) It is a fact that there is no standardized test method at NATO level, let alone an assessment criterion, for the accuracy of hand weapons:
a) when overheated after repeated firing;
b) at extremely high ambient temperatures;
c) for extreme differences in ambient temperature or other climatic fluctuations; and
d) during exposure to sun.

7) To the knowledge of Heckler & Koch, these NATO-wide undefined criteria are also so far unknown at a national level in the German Armed Forces. The only exception being in the spring of 2012, when the so-called “Realistic Combat Firing Cycle” (EBZ) was standardized for the first time, and in which the G 36 rifle, once again, was proven to meet, or exceed, the specified accuracy requirements.

8) Heckler & Koch is compelled to state that we were, at best, informed incompletely, always with delay, and as a rule not involved by the German Armed Forces in clarifying any of the recent issues claimed against the G 36 rifle, nor the investigations to substantiate them.

The continued questioning of the technical suitability of the G 36 rifle stands in stark blatant contrast of the worldwide reality of G 36 operations over nearly 20 years.

In the larger debate about the equipment of the German Armed Forces, the systematic proceedings against Heckler & Koch cannot be explained against this background, and we again request the right to have the opportunity to address any/all specific issues, by immediately conducting joint investigations, so that a fair and equitable conclusion can be reached. It is the right thing to do, for all concerned, and any continued reluctance to do so is not understood.


In response to recent media reports in Germany, commenting on HK’s ability to meet it‘s interest and other financial obligations, the company is pleased to make the following statement:

The liquidity status and financial performance of H&K is not only stable, but improving. In addition to it‘s own substantial cash reserves, H&K has available to it an undrawn line of credit of 30 million Euro, which will remain available through 2017. Additionally, the order book shows a promising trend in new orders resulting from submitted proposals and new products.

H&K‘s operations remain unchanged, with neither a reduction of staff, nor a reduction of capacity utilization.

H&K is looking forward to continued improvements in operational and financial performance in 2015 and to continuing to design and manufacture the world’s best small arms for the defense and security agencies of NATO and its allies.

Much as H&K may protest against this, there is considerable evidence that the rifle suffers from a polymer barrel bearing. A gunsmith who requested to remain anonymous shared these images with TFB:


This picture best illustrates the deformation that can occur The trunnion itself is made of steel, but rides entirely within a polymer cradle that is integral to the receiver. If the barrel is able to shift even a little in its cradle, the rifle will lose zero.


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Below, one can see how the cradle interfaces with the sighting system:


This clear plastic cutaway of the G36 illustrates the architecture of the rifle. A steel trunnion/barrel extension is permanently embedded within a polymer receiver. Attached to the polymer receiver is the optics mount/carry handle, without steel or aluminum reinforcement. Image source:



This image of an HK 243 civilian variant of the G36 highlights the carry handle/sight attachment. Due to the contrasting finish, one can see that the sight mount is attached directly to the polymer receiver, itself attached to the rifle’s barrel. Under sustained fire, the polymer may deform and the sight may lose zero.


If the Bundeswehr decides to replace the G36, it seems reasonable that they would purchase HK 416A5ss in replacement, as that rifle has already been type classified as G38 by the German government. That would be an unusual case of an AR-15 derivative replacing a second/third-generation 5.56mm rifle.

Nathaniel F

Nathaniel is a history enthusiast and firearms hobbyist whose primary interest lies in military small arms technological developments beginning with the smokeless powder era. In addition to contributing to The Firearm Blog, he runs 196,800 Revolutions Per Minute, a blog devoted to modern small arms design and theory. He is also the author of the original web serial Heartblood, which is being updated and edited regularly. He can be reached via email at


  • I can confirm that these guns have bad POI shift.
    I have sighted mine in in the winter, and then had it several inches off in the summer. Also one time I sighted it in in the cool of the morning, and it laid on its side in the summer heat at 100+ degrees for a few hours. After that the point of impact had shifted!

    • wildman0708

      How substantial was the POI shift in inches?

      • I sighted it in at 200 yards and then it was unable to hit a 6 inch diameter metal plate at that distance.

        • wildman0708

          So assuming you were aiming dead center on a 6” diameter
          steel plate, the POI would be off by a minimum of 3” in any direction. This
          does seem fairly substantial for a gun “…acknowledged worldwide as a, technologically
          superior assault rifle.” Since you own one, maybe you could do a video measuring the G36 POI shifts. Test cases could be; POI shift from sustained firing and significant
          outside temperature changes. I think this would make a great TFB article
          considering how often this topic has popped up.

          • Good idea. I will wait until the middle of summer w/ 100+ degree weather and perform it with a g36e and a g36k. Stay tuned.

          • MountainKelly

            HK will likely not be pleased if the results are consistently negative

          • nadnerbus

            Might I suggest that you also use an infrared temperature gun to check gun surface temperatures as you go along? People are saying the plastic should not be affected by a regular hot air temperature day, but black does a very good job of absorbing heat in direct sunlight.

          • Read my mind, nad.

          • This should be on TFBTV, in the name of science. I’d watch the heck out of that!

    • I still think the G36 was never meant to happen and just appeared because the G11 died early. If I want a 5.56 rifle I think I’ll go for an AR-15 (or a derivative) first, and perhaps Germany would be better served going with a 416 if only just to have AR magazines.
      Why has the Bundeswehr not adopted the in-my-opinion much better G41 is anyone’s guess…

      And I -am- a self-admitted koch-sucker, so to speak! (I take the nickname in stride, I think it’s adorable.)

      • Tom

        The G41 was about 3 times the cost of the M16A2 (and that is 1980s/90s prices) and offered nothing more than the M16A2.

        Also (and I am not sure how true this is) there have been persistent rumors that roller delayed blowback rifles do not play well with 5.56mm ammo.

        • Yeah, that isnt true.

          • That’s something I’ve heard as well. Could you elaborate?

          • That 5.56 doesnt work well with roller delayed blowback? From personal experience firing thousands of rounds through 33s and 53s I can attest that it works fine. Accurate, reliable, blah blah blah. The only negative I can think of is having to swap rollers every so often (talking thousands of rounds).

          • Well, that goes for the bigger brothers, too.

            I couldn’t for the life of me think of a reason it wouldn’t work with 5.56mm, so it was either a very technical issue or a non-issue.

          • Joshua

            Delayed roller lock guns, are not blowback in the same way handguns are.

            When someone says blowback 5.56 they do not roller locked gun.

          • 1. Correct (sans a few designs like the p9).
            2. Wat.

          • polan cannot into roller locked gun

          • Joshua

            Sorry was on my phone when I typed that. I meant generally when someone starts talking about blow back 5.56, they are not meaning the HK designed roller locked guns.

            I guess some do, but most want a rifle that function like a semi auto handgun, and that just is not possible with 62,000psi 5.56.

          • I don’t think anybody references a blowback 5.56 rifle inferring that it utilizes straight blowback.

          • Kivaari

            Wasn’t there two rifles, a case-less G11 and a Russian, where the barrel and associated parts moved back, in a straight-line, while firing 3 round bursts. Neither 5.56mm, both being combat rifles.

          • LCON

            the Russian is the AN94

          • The g11 fired a 3 round salvo burst using the operating principle generally referred to as “German space magic”. The Russian AN94 uses a weird gas trap combined with a secondary set of moving parts to send a quick two rounds down range. But “straight blowback” does not refer to the bolt and carrier simply operating in a straight line. Read up on the different kinds of blowback operation to get a feel for it.

          • Kivaari

            I wasn’t implying they were blow back operated. Each round was fired from a locked breach. A rather complex arrangement to get the rounds out so fast that they sounded like one shot. I’ve never fired a machinegun that was so fast. In shooting the MP5 at night, having a patrol car spot light on the target I was always surprised to see the cluster of copper bullets so close together, that it didn’t seem like they were sensed as being much slower. Instead of a stream of bullets they looked like a cluster of copper plated buck shot.
            The only machinegun I used that was straight blow back was the M1A1 Thompson SMG. It ran pretty slow. Everyone was complaining that it climbed off target. I found once the first 2 shots were out, you could control the gun like a water hose.
            Except for the M1919 and M60 belt guns most of my shooting was with M16A1 and the MP5. I loved the MP5, using it for 12 or s0 years as my primary shoulder weapon.

          • If we’re going to get very pedantic about it, all the HK family of firearms (as well as Kiraly-type, P7-type gas, etc) are retarded blowback. “Delayed” means something else that is rarely seen in firearms (but relatively common in autocannons).

            A breakdown of the terms:

            “Retarded blowback” – The weapon is never locked, but the mechanism has to act against some sort of disadvantage before unimpeded blowback operation can commence. Examples: H&K G3, H&K VP7, FAMAS.

            “Delayed blowback” – The breech is locked upon firing, but is unlocked through some mechanism (note the overlap with short-recoil operation here). Operating power is provided by blowback gases from the chamber. This differs from gas operation and recoil operation in the source of the force used to complete the cycle. Perceptive readers will note that this occupies a kind of gradient with gas- and -recoil operation. Examples: I believe the primer-actuated early Garand designs fall into this category.

          • The word the germans use to describe the G3 style locking system translates roughly to “half lock”.

          • Yep. The above pedantry is brought to you by George Chinn.

          • Esh325

            While your experience is true I don’t doubt it, there must be a reason why blowback aren’t used anymore in rifle designs.

          • Maintenance, weight, crude locking system that alters with heavy use, expensive to make (believe it or not relative to modern machined stuff). But it is still made by H&K in the form of the MSG90 and MP5 series.

          • nadnerbus

            I’d bet it comes from the first gen FAMAS lever delayed blowback action, and the problems they had with it with 5.56 that was not made to exact m193 spec.

            I know I get lever and roller delayed confused in my head, maybe he did too.

          • Tom

            The problem with the FAMAS (as I understand it) is that as blowback (be it straight, retarded or delayed) results in a very violent ejection cycle causing the brass to be deformed hence the need for steel cases.

            As for the HK33 not working well with 5.56mm I have no idea where I first heard this but I seem to recall it had somthing to do with the size of the bolt face or some such. Of course I might be delusional and making this all up.

            But still the failure of the G41 was I think mostly cost. Whilst the G33 was more successful it never achieved the level of success as the G3 again I think its cost. By the time the market went to 5.56mm M16s were cheap as chips and plenty of nations simple opted to copy the AR18 which could in theory be made cheaper than the G33.

        • Caleb Wise Gray

          I have also read it was stupidly expensive. Regardless, the germans were going to buy it to replace the G3 in the 80s, but reunification caused the order to be cancelled. As for why they didn’t buy it later, the fact that it weighed 9 pounds (4.1 kilos, same as the G3A3 in 7.62) may have been an issue.

      • What’s bizarre is that H&K has historically been very good at product-improvement. Why hasn’t this been fixed yet? Baffling.

        • Tom

          Maybe they can not fix it without completely redesigning the rifle?

          • I think that’s likely… And even more worrying.

        • Denial and the problems only manifesting themselves in the climate of the sandbox perhaps.

          • AlanHan

            A very large part of the militarily hot world today is “sandbox.” As for the relevant testing to duplicate the problem, I believe it is this: (Do this or careful simulate this->) Patrol for a few hours on a very hot sunny day. Engage enemy, firing even just five or six magazines, at least some of them on full auto, in an already very hot chamber/barrel. Disengage and patrol for a few more hours. THEN see how far south your zero has gone, as your barrel/trunnion’s cradle has melted, shifted, and then re-solidified…all unnoticed by the guy with the rifle until it’s too late.

        • valorius

          the german army has not included hk in the process, according to the article

      • JRT6

        HK absolutely hate the AR magazine and they made it a point of contention when designing that oversized G36 mag and their really oversized, heavy and expensive version AR mag. I also think HK screens for their ideal job candidates to have extreme arrogance.

    • MPWS

      What was intensity of use? With all due respect I can see lots of lead blasting in your videos.

      • Couple mags. The gun is equipped with a semi auto only grip stick.

    • That’s not good news, Alex. I was sitting here hoping you would come in and tell me it was exaggerated, that there wasn’t really an issue. 🙁

      • A test is in order. In 100+ degree weather this would be good to do. Sight in while cool, lay guns in sun for a few hours, shoot again. Will use a standard and a K model.

        • Weaver

          Also do it around the same temp as sight in but only shoot 60 as fast as you can. I would like to see the results.

        • Alex, be sure to bring along AK and AR pattern rifles and subject them to the same test as controls.

          • Ben

            It would also be good if that test could include a AR180 (or similar, aussie Leader etc) as the G36 is heavily based of this rifle.

            You could also add a FN SCAR as direct comparison of a similarly modern, polymer heavy, short-stroke gas pistol rifle.

            And a Sig 55x series, just cos 😀

          • I dunno if that would be strictly necessary, but sure.

          • Ben

            I only ask on the basis that it would be cool to read about, not out of any scientific/data validity concerns 😀

            Although, since this test is effectively comparing the three main operating systems in general usage and their respective representative rifles (DI – AR-15; long stroke gas piston – AK; Short stroke gas piston – G36) it would be good to have a control rifle representing short stroke gas, e.g. the SCAR.

          • I don’t feel the test would be comparing the operating mechanisms in any meaningful way.

          • colin

            Good idea but might I suggest, the arx100 instead of the scar – Polymer surrounding the trunnion area as apposed to aluminium and more relevant to the g36…

          • Oh that’s a good idea, colin.

          • Kivaari

            Years ago I read an article about the Alaska State Troopers testing many of the common military-type rifles. The rifles that worked were the Galils. In that article pretty much every rifle tested failed, except for the AK based rifles. I had used the Valmet RK62 in harsh conditions, and it did not fail. I see Alaska State Troopers use M4 carbines now, they must work.

          • This one?

            It’s worth noting that in that test, everything that’s not an AK (including the FAL, HK91, and M1A) chokes. I have always contended that the AK is a very reliable platform in cold weather; and that should be no surprise considering its country of origin.

          • Kivaari

            It probably is, my computer wont down load the article.

          • If you still can’t DL it, email me and I’ll give it to you.

        • Kivaari

          You could do it at any time of the year as long as you had and oven and freezer handy. This is actually the first time I read much about the G36, as the non-existent of civilian rifles, at least to me, left me thinking I don’t want one. Now I know I really don’t want one. Seeing the melted interface and the scope-on-plastic mounting system tells me I shouldn’t ever want one of these. What were they thinking – beyond big profits – that used this silly design?

          • Yeah… Most ranges dont have an oven or freezer on sight.

          • Kivaari

            A few family members had their own range, next to the barn with the walk-in cooler and a way to heat the guns with “heat bulbs”, placed closer than a chick rearing box. We had access to a headlight battery checker (I am so old) with 16 head lights. I miss having a range so handy.

          • valorius

            im pretty sure we can leave these tests to the bundeswehr and hk for sorting out, lol.

    • n0truscotsman

      That tells me it wasn’t the ammunition like what was originally claimed either. Unless you were shooting that ample supply of German 5.56 that is available and everything 😉

      • Not sure what the deal with the claim about it being the ammunition was.

        • Mark Dietzler

          It’s H&K, they always claim it is the ammunition. Because you suck, and they hate you.
          I’d like to meet the genius who thought surrounding the hottest part of the barrel with polymer, and then attaching the sight directly to that polymer, was a great idea.
          I would imagine that replacing some of that polymer receiver with forged aluminum would work to fix a lot of the issues that rifle has, but instead H&K will charge ahead, confident that their way is the Only Way.™

    • Yallan

      How had this problem not been found? Seems pretty severe, and why has it come out only recently? The guns in been in use for 20 years almost.

    • rnf

      I talked about G36 problems to ex fallschirmjäger sergeant, 2 or 3 months after this issue surfaced couple years ago, and he straight up confirmed that too.
      And as a additional information, he said that first G36’s had even bigger problems – you could flex the rifle diagonally, in hands even, for example pressing rifle against shoulder while aiming. That issue was apparent especially after emptying couple of mags, and because of that accuracy suffered greatly. He said that in early days of G36, KSK soldiers even refused to use carry handle/scope combo standard rifles, because of that flexibility/accuracy issues. H&K made an aluminium flattop/rail variant for KSK, mainly to fight that flex issues – metal rail added rigidity. In later production years H&K learned how to stiffen up standard rifles so the flex issues where not so apparent and problematic.

  • Samson

    HK sure reminded the world that we collectively suck and they hate on us. All of us – equally … Enough hate for HK to spread around to all of us suckas …

  • Michael

    Not a H&K fan myself, but before the bashing starts, I reccommend looking at Vuurwapennlog’s article on why H&K does not suck.

      • jack c

        You mean the article you plagarised from vuurwapenblog?

        • dan citizen

          not cool.

          TFB does not plagiarize.

        • I sourced a bit from Andrew, but we talked about it over the Internet and in person and he is cool with it. You can see clearly the block quote he said I could use and I gave him due credit.

          • jack c

            You only attributed it to him after being called out on it, you didn’t exactly enshrine yourself in glory.

          • I have attributed to him before “being called out on it”.

      • Michael

        I had not seen that one yet.

    • AlanHan

      I believe TFB’s (and Andrew’s) explanation of the long-term failure of HK to export its attractive weapons contains a blaring error. The article states (and attributes back to Chris Kyle) the following:

      “First of all, German export laws are just as if not more complex than our import laws. You see, the German government effectively owns the patents and export rights of all firearms made in Germany, and it takes years to get approval for the exportation of even military rifle designs to H&K USA!”

      This is simply wrong. The German government does not effectively own the patents and export rights of “all firearms made in Germany” but rather only and specifically for firearms which have been sold to the German military. It is THAT bit from which H&K has been vociferously seeking relief for years. This isn’t my field of law, but I believe HK has recently received hope of such relief. They should have pursued the matter years ago, based on a “semi-auto only” exemption.

      I personally think the problems run deeper: In working up the HK45 pistol HK had tremendous sources of solid advice. They choose to ignore much of it. Specifically they ignored Vicker’s advice on the trigger design (and grip…). Who in the civilian or police world wants a pistol with a second-rate trigger? Nobody. Sure, some devotees will buy it and make it work, but mass sales were hindered. I personally would have purchased an HK45 if there was a model whose trigger package (total feel and function) suited me.

  • TunTun

    Holy cow! I had no idea the receiver was polymer! Learned something new today thanks TFB. This explains a lot…

  • Vitsaus

    They could always see if Colt will share some notes on how to spin these kinds of situations. It worked here, should work in Germany too. “The troops weren’t maintaining them right, they were issued the wrong ammo, it needs some special lining on the surfaces, etc….”

    • If true, this is a way tougher PR situation for H&K than any Colt’s had to deal with, in my opinion.

      • Vitsaus

        How many Bundeswehr soldiers died in fire firefights because of this flaw? I think the casualties caused by the problem will determine how much of a PR nightmare this will be. In my opinion.

        • Oh, you mean back in ’68. Yes, that was a bigger can of worms.

          • Vitsaus

            “If true, this is a way tougher RP situation for H&K than ANY Colt’s had to deal with…” not sure which other one you might have thought I was refering to, and as I originally stated, the PR spin would still be usable today, of course.

          • My mind was on the M4. Mea culpa.

          • A.WChuck

            Wasn’t the Colt issue caused by the US Military changing the powder-type and not issuing cleaning kits? What am I missing?

          • Chrome-lining and case hardness specs were also major factors.

            A reasonable short version of the story is that the DoD accepted manufacturer claims that the AR-15 was an “off-the-shelf” weapons system that was good to go. In reality, the AR-15 had not yet had a proper development cycle, and a totally new rifle and caliber were fielded to Vietnam without what I would consider prudent testing.

            With the M16A2, the AR-15 finally reached a proper level of maturity, but frankly that should have happened much earlier.

  • Isaac Newton

    good explanation for what the problem could be.

  • Seburo

    In the firefight in Afghanistan that spurred the controversy, G36s were fired back to back nonstop on auto, even the G3s were malfunctioning due to the sheer ROF they were subjected to (about 11 magazines back to back in a very short time frame). It seems like a lack of training and discipline on the part of the German Army in addition to not asking HK fix the rifle after finding melted polymer on their combat rifles.

    If their going treat their rifles like that they may as well buy M27s, along with more MG4s and HK121s.

    • dan citizen

      “even the G3s were malfunctioning”

      Then no lesser rifle stood a chance.

      • Seburo

        I’m starting to believe the reputation of the old Cold War Battle Rifles are exaggerated except for the FAL and Dragunov.

        • Vitsaus

          Except when you consider that the cold war battle rifles that are still in service might but up to 50 years old and well past their “use by” date.

          • In the case of the M14s, that just means they’ve been in storage that long.

            It’s worth noting that the G3 and FAL stayed in production for a long time, too.

          • James

            I love my FAL to death, and I have a health dose of respect for the G3 family, but I’m smart enough to recognize that they have their failings, in weight, accuracy (the FAL’s front and rear sights are on two separate receiver halves, for goodness sake) and customization. That being said, they don’t melt in direct sunlight, which is a plus.

        • M

          IMO the reputation of the FAL is exaggerated as well.

        • dan citizen

          I don’t agree. The G3, FAL, AK, Dragunov, and their derivatives had and still have exceptional sturdiness.

          They were not superseded because they performed poorly, but because they were heavy and pricey.

          The weapons that replaced them are primarily lighter and cheaper, but not more powerful or more reliable.

          • Couldn’t speak to the G3, really, but I’d be willing to bet that in certain important parameters an AR-15 runs rings around an FAL for reliability.

          • dan citizen

            I agree. Imagine if Germany had just adopted an AR?

            Probably would have saved some $$$ and headache.

    • Weaver

      Is there some why to look up the battle report?

      • Seburo

        I wish. I had to find this on HK PRO and on an old thread.

    • John

      >even the G3s were malfunctioning due to the sheer ROF they were
      subjected to (about 11 magazines back to back in a very short time

      The thing is, that’s only 220 rounds total. If the German G3s were failing after that little expenditure of ammunition, even at full auto, then there is something very wrong with the German army’s arsenals to begin with.

      • Seburo

        That would actually explain a whole lot. Although the G3s can fail due most of them being really old. Nor are they true DMRs.

  • MPWS

    The mentioned cradle, is it same piece of material as receiver or separate? What material is it? Word “polymer” does not describe it well enough.
    Besides, there are materials lately, which can withhold large amount of heat and than release it slowly into surroundings; kind like “accumulators of heat” with slow release.
    Furthermore, what was projected lifecycle of G36 to begin with?

    • William Litten

      The G36 receiver is created by placing a steel trunnion inside of a mold and then injecting glass filled nylon (or some variation of it) around the trunnion. Its actually a very clever and cheap way of making a rifle much like stamped sheet metal was decades ago. Obviously there will be issues with the trunnion expanding inside the plastic receiver under sustained fire.
      That said I find it hard to believe that sitting outside in the sun for several hours would cause significant Point Of Impact shift. But I have never owned or fired a G36, so what do I know.

      • MPWS

        I did hold it and fumbled with it – and was not impressed. In concrete terms, with disassembly and loose pins. I also lost firing pin in doing so.
        As far as previous gen of roller locking rifles, I liked them. So I am not anti-HK loaded.

    • It’s a part of the receiver.

  • DIR911911 .

    a little JB weld will fix that right up 🙂

    • Miles

      You may be closer to a possible solution than you realize.
      A high temperature resistant version of JB for gluing the trunnion to the polymer receiver might just work.

      • That wouldn’t solve the thermal expansion issue polymer has.

  • Riot

    I am slightly skeptical that the germans and not the spanish, portuguese, malaysians or even jordanians are reporting this problem.

    • Vitsaus

      That occurred to me also. Or the British who use the carbines widely in security roles.

      • Bill

        I believe even the US Capitol Police were using them. It’s not Africa, but DC in the summertime, their outside guys would get little sun umbrellas to stand under…..or maybe those were to keep the rifle cool……

        • A.WChuck

          How many rounds do US Capitol Police put down range? Is it even enough to get the weapon hot enough to see the problem?

          • Bill

            I gotta learn to stop being sardonic on the web.

            In all actuality, it’s probably a lot more than you’d think, it is the freaking US Capitol they are protecting, and they have all the toys. 700 some officers covering approximately 70 facilities. SWAT, HAZMAT, CBRNE, EP, EOD, physical security, they do it all.

          • Dracon1201

            Oh, and that means something? Because it really doesn’t. They don’t become instant firearms aficionados who decide to become world class marksman.

          • Bill

            You’re right, the men and women who protect our major government facilities and personnel would probably be better of with rubber-tipped bows and arrows or super-soakers. They might as well convert all the FLETC ranges to airsoft. And the Air Marshals have only shot one guy in their entire history, why even bother giving them guns?

            I gotta learn to stop being sardonic on the web.

          • n0truscotsman

            That may be true, but the advantage of having an American law enforcement agency or civilian population test such firearms is that we shoot them. A lot.

            We find problems that other countries couldn’t even imagine because that is how you test firearms. You shoot them lots. This doesn’t happen in the Bundeswehr.

          • A.WChuck

            My point was meant to express that police forces are rarely in prolonged firefights were the weapon temperatures reach their design limits. I doubted they used them enough, even in training, to get close to limits. Maybe the G36 is so troubled CP saw problems even with their lighter -than-military usage?

          • Bill

            Your point is well-taken: if we (the police) are in prolonged firefights, we are doing something wrong, like missing too much. Before my brother and sister officers start screaming, their are outliers, like the North Hollywood bank robbery, where bunches of rounds are fired, or worse, like the post-Boston Marathon shootout, where way too many rounds were fired.

          • Nicks87

            They shot their 36’s enough to recognize the problem and move on to a new weapon system.

        • Nicks87

          The Capitol Police experienced the same issues with their rifles. I believe they have since moved on to 416s

      • Tom

        Never gets that hot in the UK and our police do not fire that much outside of air conditioned indoor ranges.

    • Sianmink

      Maybe it’s only the Germans who have actually seriously fought with the thing and gotten their rifles toasty hot. I mean, I wouldn’t rule it out.

    • Doesn’t Mexico use the G36? Have they had issues with it in their hot climate?

      • LCON

        Mexican Police Use G36 carbines, the Mexican Armed forces moved to a indigenous weapon called the FX-05 “Xiuhcoatl” which is heavily influenced by G36 especially early models which caused some claims of copy right infringement. But HK them selves investigated this and gave the Mexican’s the Okay… Speaking of which I think the recever of the FX-05 is also injection molded thermo plastics so it might have the same issue.

        XM8 was a derivative of the G36C and shared the same bolt and gas system design but it’s receiver assembly broke down more like a M4’s then a G36 It also likely would have had the same Trunnion.

        • Uniform223

          “XM8 was a derivative of the G36C and shared the same bolt and gas system design but it’s receiver assembly broke down more like a M4’s then a G36 It also likely would have had the same Trunnion.”

          When I was younger I bought into all the hype about the XM8 being a lighter more “reliable” platform as well as with all the piston driven stuff. Older and more mature I am happy the US military did not adopt the XM8 if it indeed had the same barrel trunnion design. Also with the M4 using early KAC RIS, this gave the M16/M4 platform greater user options of modularity and customization… something the XM8 didn’t look like it would have.

          I believe that no matter what boat you choose to float in, everything out there now does essentially the same thing but with different mechanics. So to me, trying to beat your chest and drum in a vain attempt to prove one is leaps and bounds superior over the other is very narrow minded and moot.

    • J Garcia Sampedro

      In Spain we are having this problem (and MANY more) since before the G36 was selected among those tested in 1996 for replacing the CETME L.
      During the tests many “special rules” were added and modified, and it was clear to us they wanted the G36E to win (politics, and compensating Germany for selling Santa Barbara to General Dynamics).

  • J.T.

    HK is in denial. They are pretty much arguing that the guns are fine because there are no problems when firing the gun on a rifle range where it doesn’t heat up much and saying everyone should ignore the POI shift issues that have cropped up in real world scenarios.

    • nadnerbus

      What I got from their press release was, they have it designed perfectly to all German technical specifications, but that a “new” test or tests was conducted on the rifle that was never speced to them in the original design (high heat), which they can’t address because they were not part of the test.

      It leaves enough room in there to weasel out by saying “we designed it to spec, this wasn’t in spec, it’s the Bundeswehr’s fault for not specing it to begin with.” At least that is how I am reading it.

      • Hedd Wyn John

        That’s what it looks like.

        • Miles

          And it’s what lawyers get paid for; To parse the words of a contract as finely as possible!

          • Michael

            And that is exactly where german ministry of defence failed miserably the last decades, at least according to an article in last weeks german newsmagazine DER SPIEGEL: constantly being outwitted by the contractors, so no or no substantial compensation is possible if a program fails (miserably).
            And besides: of course H&K follows the “we followed specs”-line. So it’s not there fault, when specs are wrong – they still made the perfect product for – imperfect – specs.
            And I won’t go to the German tradition of “we do what we’re told”…

      • Morogan

        Wel they designed a cheap, lightweight and accurate rifle that should be used in single schot mode for the bundeswehr. becaus thats was what was ordert. they deliverd true to specs. but over the pas 25 years the role of the germany army changed en they saw some pretty heavy firefights in Afganistan. here the found out tha that the rifle had these accuracy problems. so now they call it a bad rifle…. true it doenst do the job it needs to do these days. but back when they orderd it id did what it was supposed to do.
        Encasing the trunion in polymal wasnt a verry good idea. but it was cheap (remember the bundeswehr wanted a cheap rifle) and did the trick if the rifle was fired in singel shot mode in regular german weather

  • USMC03Vet

    That melted plastic is pretty damning.
    Nice pictures!

  • dan citizen

    Great article. well illustrates the issue.

    I can’t imagine why this barrel/trunnion/receiver arrangement seemed like a good idea.

    • It is very cheap to do it that way, and H&K was bankrupt.

  • BrandonAKsALot

    Not surprising once you see the insides and where the optics attach. There is a reason most rifles have the sights or sight attachment areas made of metal and attached to the trunnion or barrel extension directly with metal. Polymer has too much flexibility and expansion.

  • toms

    I have a hard time believing that these problems did not come out during the light machine gun G36 version trials. It had to have had some pretty extensive firing regimes. The fact that their is a correction package leads one to conclude that this is a legitimate problem. I imagine the fix costs almost as much as a new rifle. It would have to involve a new barrel,triunion, and barrel assembly plus HK labor.

    • AlanHan

      The photos make clear that a fix requires a replacement receiver. The trunnion is fine. The cradle/receiver is screwed.

    • n0truscotsman

      I think the fact that the G36 IAR wasn’t issued or sold was pretty telling.

      • Joshua

        But, but, XM8

        • n0truscotsman

          …in 6.8 spc of course 😉

  • Don Ward

    They all mocked me when I warned about the dangers of placing too much faith in those fancy polymer contraptions. Now look who’s laughing? Now look who’s laughing now?!?

    *Mad cackling*

    *Castle thunder*

    Soon the gun world will come around once again to the wisdom of proper wooden stocks. And I’ll already be there.

    *Lovingly pats down the potting soil around a walnut and then waters it*

    All I have to do is wait.

    Any day now.

    Any day now…

    • Isaac Newton

      There is nothing wrong with using polymer in general. No guns that I know of with wooden stocks mount the optics/sights to the wood, but I would expect similar poor behavior with moisture/heat.

      • Kivaari

        Like the simple change Brits did to the No4Mk2, they moved the trigger pivot from bing mounted on the stck, to being attached to the action. In earlier models the trigger pull changed as the moisture content of the wood changed.

    • Kivaari

      I knew there was a reason I like the M16/AR15 based rifles. I love polymer gun parts in the right place. The best pistol I ever used on the job, was a Glock 17. Why HK used this system is baffling.

    • MadDog Arma

      Russians still use wood because it does not freeze hands in artic conditions. It also is more comfortable in hot desert conditions. The polymer buttstock of the M16 was however ideal for vietnam as it was virtually indestructible. The Swiss Sphinx SDP only has the grip made of polymer. The Walther CCP has the slide riding with a piston, completely floating over the polymer. I always felt funny about direct slide to polymer interactions, and in this case a hot barrel like this does not seem wise. Wood would be indeed a better insulator.

      • Kivaari

        The failure of stocks on M16s was a reason the change was made to the M16A2. While serving as an armorer, the most changed items were butt stocks and hand guards. The A2s are made with superior materials.

        • The Brigadier

          I agree, it was a problem, but the A1 went from single shot to full rock and roll, and the A2 only to three’s a crowd. I still carried a M14 whenever and wherever it was possible to complete with a beautiful walnut stock.

      • Angus

        russians don’t use wood they have polymer on their rifles now

  • roguetechie


    I called this awhile ago when the Germans stopped even buying spares for the g36. But really this shouldn’t be a surprise to anyone with even a basic understanding of materials science. I mean it’s why they put expansion joints in friggin’ bridge decks for the love of god!

    Stuff like this and HK’s response to it is why I consider the products they are marketing now, and working to complete and bring to market, a total joke.

    Come on guys, is this really a surprise? They put two materials with wildly different behaviors under the thermal load EVERY RIFLE should be designed to work under in direct contact with each other in a way that each depends on the other for proper alignment… and then act like its a ****Ing surprise when this happens…

    What you thought changing the body style from XM8 Which also reportedly had the same damn problem would make it magically change?

    The meme shouldn’t be: HK because you suck and we hate you to HK you only want our products because you can’t have them…

    • Rogue, it’s been something I have been keeping a close eye on for a while. Now I feel we have overwhelming evidence that the G36 is a deeply flawed design and that there is no easy fix for it. It was Alex’s comment that put me over the edge; I’d read the news articles, looked at the design, and even had evidence of receiver melting in those images I posted (which I’ve known about for years), but when you can shoot the rifle and see the POI shift… That’s it.

  • iksnilol

    I lost my faith in German engineers when I found out that somebody thought a polymer covered trunnion was a good idea. Especially when everybody went along with it. Then to add insult to the injury they add the optic rail on polymer also. And to make things far worse, they made over 100 000 of these rifles and nobody thought about fixing these issues.

    When a person who isn’t an engineer can see obvious engineering flaws then that is bad… Real bad.

    • nadnerbus

      So I shouldn’t design my new car to have it’s engine block mounted in polymer?

      • iksnilol

        It would be…uh… inadvisable. Yes, that’s the word. In-ad-vis-able. Not mindbogglingly stupid but inadvisable.

        • Bill

          Actually, it probably has some sort of poly bushings to cut vibrations to the chassis and motor mounts.

          • Vhyrus

            You are right, but the polymer is sandwiched in between steel plates to isolate it from heat.

          • S O

            “(…) the polymer is sandwiched in between steel plates to isolate it from heat.”

            That perfectly makes no sense at all.
            What would make sense is if the engine simply has enough of a tolerance for the drive shaft that temperature change-driven changes in dimensions are acceptable.

          • Kivaari

            And to isolate the vibrations from the passengers compartment. Vibrating like a Honda 360 wears a person out.

          • nadnerbus

            Jane Fonda wouldn’t know, since Fonda aint got a motor in the back of her Honda.

    • Tom

      This also does not speak well of the Beretta ARX 160 ether. Time to accept that receivers need to be made of metal not plastic.

      • I don’t think the receiver portion being plastic is a big deal, it’s when the sighting system and barrel interface via plastic that you get thermal expansion issues.

        • S O

          Thermal changes lead to expansion or contraction (with cooldown) of material. It’s all about the geometry whether zero will be lost. It could just as well be that changing from one material to another means the sight or rail is elevated by 0.03 mm equally front and rear instead of 0.02 mm, for example. Geometry can change this to an uneven influence front and rear.

          • Kivaari

            I suspect the rate of expansion between the metals and plastics is quite different as well.

      • iksnilol

        The receiver isn’t the problem, the problem is that the trunnion and the connection for the optic is plastic.

        • Kivaari

          And the sight and barrel are not held rigid, to each other.

        • AlanHan

          The trunnion is steel. It is the cradle for the trunnion, which cradle is molded onto the trunnion at injection time, that is the polymer problem.

          • I think the official terminology for the steel barrel extension is “trunnion”. IMO, normal terminology would have that as the “barrel extension” and the “trunnion” would be integral to the polymer receiver.

            Regardless, the effect is the same.

        • Tom

          The reunion is metal (on the G36) but connects to the polymer receiver. I believe the ARX is the same.

    • MR

      I lost my faith in German engineers when I had to work on a Mercedes SemiTractor engine- utterly rediculous garbage. Then a Sprinter pulled in, and that’s even worse. They seem to think that the more complicated and fragile something is, the better it must be.
      Their suprise that their rifle should work even when the sun is shining reminds me of “Deal of the Century”, when the drone malfunctions after being washed. “Have you ever heard of rain?” Oh yeah, H&K, people will expect your rifle to function in the rain, too.

      • Kivaari

        Excellent comparison. I never understood why so many people think Germans make great anything. Look at WW2. Thank God Hitler’s people couldn’t stick with known functioning implements of war. His crew wasted so much on bigger and more complex designs that they failed to make more things that worked. The “Great Tiger Tank” that lost out to field mice, produced in the hundreds while Russian T34’s were coming out in the tens of thousands. So, simple they drove out of the factory into battle. Super artillery moved by trains and having crews of hundreds, when had they made more 8.8cm cannons they might have won. Thank God the Germans were so dumb.

        • MoPhil

          You forget about the advantage in ressource availability, which the UdSSR and the US had. Both, US and UdSSR had oil, iron ore and any other materials, their war machinery needed. Germany had very little iron ore, next to no oil and the transfer of these ressources from the occupied territories to the production centers (most of them were located in Germany) was getting more difficult when the war progressed, since the US and the Brits not only bombed innocent civilians, but also the infrastructure. But you are right, there were some severe miscalculations made in the leading ranks. The first jet fighter was already flying around August 1939, even BEFORE WW2 started. It was the He 178. Imagine the Luftwaffe had dropped propeller driven planes and switched entirely to jet planes from the first days of the war. The Battle of Britain would definitely have had a different outcome and so maybe WW2. Nevertheless, it came differently. But fact is, that, although Germany had such a sh*tty govt., which made many many mistakes in that time, it withstood the British Empire, the USA and the UdSSR for around 4-6 years, which I think, is pretty impressive.

          • Kivaari

            Germany’s governments are exceptionally stupid. No sane nation would start a war knowing they need raw materials in other nations to build basic arms. Biting off more than they can chew has been a historical German failure. Japan did it as well. Axis nations all needed raw materials of others to conduct war against others. Japan and Germany were particularly racist. Had they wanted to improve the lives of the citizens, every thing they needed for those people could have been purchased. Since all of them desired too much for the wrong reasons it led to war. Killing innocent lives by the allies, made sense. Killing enough of the enemy and infrastructure was needed.
            Too bad for the people, even the individual soldiers, with no desire to kill innocent people, but being forced at gun point to kill, made them fair game.
            Like WW1 a spat between the royal cousins resulted in millions dead, all for no good reason.
            We’ll see it in the Islamic world, as the nuts will do so much damage, that they will bring about WW3.

          • MoPhil

            I fear you think history from its end, studded with a huge amount of false information and therefore I forgive you your wrong historical interpretation out of unknowing. Also TFB is not a platform for historical or political discussion, so the last thing I say about this topic is: Germany’s governments were not more or less EXCEPTIONALLY stupid, than any other unsustainable govt. is, i.e. like the US-govts since 1913, when they turned themselfes in to a privat bank syndicate called the “FED”. Now look where they are, the “great” US and A: approximately 50 million people on food stamps and a national debt of almost 18 trillions USD. If that’s not exceptionally stupid.

          • Kivaari

            Germany had too many gun designs they tried to put into service at the wrong time. It is why they never issued a truly functional semi-auto rifle in reasonable numbers. Too many different paths which denied the German soldiers good gear. Too much spent on weapons of limited usefulness. The two World Wars were fought for the wrong reason and with a hodgepodge of weapons. Neither Japan nor Germany entered the war with adequate supplies of what was needed. The desire for materials, so they could conduct wars, was why the Axis lost. Japan had been at war for 10 years before Pearl Harbor, seizing territory with those materials needed for war making.
            Germany did the same, seize land with raw materials and factories, so they could seize more land. Needing to make weapons for war drove the war. Neither nation needed to go to war. Had they simply wanted to improve their nations they should have simply bought what was needed for industry and agriculture. That need for weapons that were not needed had they been thinking clearer.

          • mosinman

            thier jets would have had many issues that jets had in 1945 and beyond, like excessive fuel consumption, flameouts, the need for high temp materials that were not widely available at the time….
            then after they got over all that old hitler would have wanted them to be fighters and dive bombers

          • MoPhil

            Correct, the at-the-time best technology is useless, if it isn’t used the right way. See the G36 and its polymere frame.

      • iksnilol

        Mercedes? Never really liked Mercedes. But VW and Audi on the other hand are awesome (so are Porsches but I can’t really afford one).

    • Kivaari

      German engineering excellence has been over rated for a century. Germans can make junk just like everyone else. Some of the guns have been described as a “machinists dream”, when all I saw were bad dreams. Look at the barrel on the Walther P4, all those extra milling procedures and the gun couldn’t shoot better than 8 inch groups from rest at 25 m. Over-engineered beyond common sense. The last good design Germany had was a K98.

      • MoPhil

        That was developed in a time, when we had a very sustainable form of government: monarchy. After that, all became worse for Germany.

      • iksnilol

        I don’t know, the G3 is a good design. So is the P7. And if we move away from guns then we also have VW. I am not a car guy but I like VW, nobody I know has had problems with them.

        • Kivaari

          You might enjoy reading consumer report auto editions. The owners love ’em, but they spend more time in the shop. Like Range Rovers and Volvos, the owner like the “status symbol” of being so cultured and smart that they bought European cars. Over 12 years ago Washington State Patrol used Volvo station wagons for the ADAT program. The Volvos were in the shop way too much. It was fun to see a trooper stopping other Volvo drivers, I wondered if the troopers were wearing Birkenstock shoes as well.

          • iksnilol

            I never mentioned Volvo or Range Rovers. I just said I haven’t had problems with VW and Audi, those few issues that were had were fixed at home. There is a reason they are so popular. And looking European isn’t a sales point anywhere outside the US.

    • Rusty Shackleford

      Technically, the G36 was designed and developed by the British Aerospace’s Royal Ordnance Division.

    • Paul Joly

      That’s not an issue to put the trunnion or the barrel in any material till it fulfill all requirements. Extensive tests has been made on both the G36 and XM8 family without making these rifles unsuited for combat.
      We heard a lot of accuracy issues after heavy fire because of barrel bending due to a lack of stabilization of the steel. That “may” be the case here.
      That also may be due to a change of the polymer’s properties due to aging.

      In any case, we should wait for a rigorous test before making any assumption.

  • MountainKelly

    I’d be interested in seeing some field reports or anecdotes if any are around. That’s pretty bad news, I look forward to seeing further testing. Rough times for the Bundswehr if this is systemic

  • nadnerbus

    So engineers, if this is proven to be a fatal flaw, what would you do to fix the design? Replace with a steel trunnion? As I understand, the G36 is already heavy for being mostly polymer. Also, wouldn’t the metal trunnion just heat up and transfer heat to the next closest piece of plastic i.e. the rest of the receiver?

    • Weaver

      The best course of action would be to do what beretta did and put a heat resistant ceramic around the trunnion. This would completely remove the contact of the steel trunnion and the polymer.

    • Great question, nan. My understanding here is that two things are occurring that cause problems in the G36: First, the polymer is expanding during heating and cooling, and the only link between the barrel and sight is through the polymer receiver. The second is the permanent deformation of the polymer receiver under more extreme thermal loads.

      Weaver’s solution of using a ceramic “firewall” is certainly an interesting one, but it does not solve the issue Alex reports of the polymer expanding even in direct sunlight.

      I do not think the existing G36 can be full fixed via anything short of an extensive hack-and-weld overhaul.

      To fix the design, the simplest method would be to change the materials used for the receiver. Most obviously, a switch to aluminum would eliminate this issue, though it would almost triple the weight of the receiver. The original receiver shape could probably be retained through forging.

      This would increase cost and weight, which obviously encourage looking for other solutions. One might be to select or develop a polymer with a low coefficient of thermal expansion and a high melting point (I am not certain of the degree to which high performance thermoplastics like PPS* are suitable for this application, it really is a question for a polymer engineer). Another might be to change the architecture of the receiver to accommodate a cantilever sight mount that would be independent of the polymer receiver.

      *PPS data sheet available here. The coefficient of thermal expansion is 2.5×10^-5, which is very low for a polymer, but still about twice that of aluminum.

      • Weaver

        How does the arx-100 rail attach to the receiver?

        • I am not entirely sure. It appears to be pinned to the polymer receiver, but I don’t know.

    • Isaac Newton

      I would vote directly mount the features that hold the optic to the barrel. This should help the issue if the problem is caused by thermal expansion of the polymer, but I suspect that a major contributor is the changing of the stiffness (elastic modulus) with changing temperature, this in turn can change harmonics of the barrel and how it behaves when the bullet is still in the tube.

      • nadnerbus

        the problem with that is that the optic/sight mount becomes a heat sink in itself and can cook a red dot pretty good.

    • n0truscotsman

      An aluminum receiver and M4-style stock would be the first modifications Id recommend (no need for a side folder and the current stock is HORRIBLE). And the removal of the carrying handle and modification of the charging handle into a non-reciprocating one. Or, more drastically, sealing off the bolt carrier completely.

      Another option is to have an extended aluminum or alloy “skeleton” that holds the trunnion. You would still have heat affecting the polymer, but the trunnion would be held secure by a material that is less profoundly affected by heat. This, of course, can also secure the optics rail.

      But at what cost?

      It would probably be heavier and expensive. It would definitely be more expensive than a M4.

  • Lance

    I don’t think the G-36 will go. The Germans invested too much into it. I they did goto a new rifle it be the HK 416 since they do share some parts (Piston). Its kind of sad always thought the G-36 was a cool rifle. Good thing we didn’t adopt in 04 as the XM-8.

  • Lance

    I personally think if they want another good German 5.56mm rifle adopt the HK 33!

  • ghost

    Maybe they built what the army wanted, and it don’t work that way?

  • Yellow Devil

    Wasn’t H&K contracted to work out the polymer (similar, if not the same) deficiencies in the British SA80/L85A2 some time ago? Did they just forget those lesson or did they just say, “Nein we will do bitte than z British”?

    • The L85 does not use very much polymer. It is predominately steel.

      • Yellow Devil

        I thought the original SA80 rifles had polymer hand-guards and some other parts? Granted I never handled it, so I can’t attest to the complete makeup of the rifle.

        • The handguards and butt, I believe. Nothing critical to the weapon’s accuracy, so far as I know.

          • Yellow Devil

            Ah I see. I did see some British chaps touting their latest (?) models downrange last year, but I don’t recall any polymer on those models, mostly fancy rails that are all the rage. Most of them seemed more excited about their Glock sidearms than their main rifles.

          • Yes, most L85s now are equipped with aluminum Daniel Defense rails for accessory mounting.

    • Grindstone50k

      H&K did do the improvement work on the L85A2, but it was mostly for function, not structure.

  • I have updated the article with clearer and more comprehensive sources. I recommend anyone with an interest in the G36 rifle give it a second look.

    Thanks for reading, guys!

  • Alex Nicolin

    Clearly a bad design. They should have thought at this from the outset. Plastic warps, bends and even melts at the temperatures encountered during prolonged shooting. Upper receivers shouldn’t be made of anything other than metal, preferably aluminum, which is also an excellent heat sink and dissipator.

  • S O

    I’m a bit surprised that even this gun blog and its audience seem to be fixated on this accuracy issue. Hardly any infantryman aims well in combat, so the issue is close to non-existing up to maybe 200 m distance. A quick shot and observation of impact helps to predict the deviation and correct for future aimed shots.

    The G 36 is ripe for replacement due to a completely different reason; its combo sights are poor by today’s standards, and the design was finalized before Picatinny rails were standardised. The vast majority of in-service German army G36 have no rails whatsoever, and the needlessly high sights increase the shooter’s silhouette as a target and cause centre of gravity issues with night sights.

    A sensible decision would be to remove the internal and other removable elements from all army (Heer) G36 and to join them with new gun stock. With powered NATO rails. Luftwaffe, Marine and Streitkräftebasis don’t need to change anything. The should have stuck with the G3 in the first place.

    • My understanding is that the POI deviations can get quite dramatic (I will check my source, but IIRC you could see something like 50cm deviation at 200m). It is apparent that the Bundeswehr ia thoroughly unhappy with the rifle.

      • Source (they do not give the range). Please note that Google Translate likes to translate “zentimeter” (centimeter) to “inch” for some reason.

        Bundeswehr being dissatisfied with the rifle.

      • S O

        Extremes don’t matter. There are always bad apples.

        Infantry G36 can be expected to experience a change of ambient temperature of about 20 K within 24 hrs only.
        Range training would be all but impossible if this had substantial impact on accuracy, since common Bundeswehr rifle raining ranges are 100 or 300 m, and the live fire areas I know were 30-450 m.

        This rifle was kept in service for two decades, more than one decade of it without noticeable complaints.

  • Alex Nicolin

    Plastic marvel

  • LCON

    The Issue is the mating of a Polymer upper to a steel barrel being used in a Automatic weapon system.the best Correction without tossing the weapon would likely be to replace the polymer Upper Receiver shell with a identical Upper made of a light weigh aluminum alloy only the barrel and Trunnion needing to be installed. because of the G36 Design is modular every other existing part of the G36 could then be retained, including hand guard, stock, mag well, pistol grip with trigger group, Stock, bolt, and sight bridge, gas system and more.

  • n0truscotsman

    Here is the obvious solution to the problem

    • Joshua

      Nah, I’d much rather have the M4A1 I was issued with the SOPMOD items. Much better rifle overall than the M4 the Army issued.

      Though the M4A1+ has promise.

      • n0truscotsman

        That is true, although my argument was really in favor of generally issuing a Stoner-type rifle, whether it is a M4A1+ or a C8 😉
        There are a dozen reasons off the top of my head why that would be a good solution for not only Germany, but also France.

        • The HK 416A5 is already type classified as G38 and would result in the least protest from H&K. Seems like a natural choice.

          • Joshua

            Expensive to.

    • LCON

      if the did change it would be to the G38 more or less the latest HK416 variant already in some German use.

  • AlbertEinstein

    This could be Bad news/Good news/Bad news with a possible silver lining. The first bad news is for the German military that may end up scrapping a flawed G36 into parts kits. Good news for North American and other shooters: Potential cheap parts kits for a highly desired but unavailable rifle! Bad news for those same shooters: It would still be a flawed design. Possible silver lining: An overnight cottage industry of US made billet aluminum receivers…… Which should have been the material of choice for the original design.

  • n0truscotsman

    That reminds me of the power train schematics for the Panther tank.
    An absolute rube golbergian pipe dream.

    Combining those tracks with the interwoven road wheels, you have something that purrs like a kitten when it works. When it freezes, or has to operate in the Rasputitsa, you have serious problems.

    I actually admire the US sherman for the very reason for its mechanical simplicity but high quality of production.

    • mosinman

      this is why i cackle with glee as people over hype the tiger and panther. overweight, and too complex. like you mentioned they had nice ideas but pulling off almost all your interleaved roadwheels to change one torsion bar is absurd.

      • n0truscotsman

        I’ve gotten in many heated debates with people that thought the panther and tiger were the most revolutionary tanks ever conceived. That, by golly, without them, we would still be fighting wars in in Chaffe light tanks according to them.
        The only good thing about either one IMO, were their guns and crew layout, which was what made them fearsome killing machines. The skill of their crews especially.
        Their chassis were absolutely horrible. Lack of availability only served to drive a stake into the Wehrmacht’s total combat power, especially since the US and Soviet Union produced utterly ridiculous quantities of tanks.
        IIRC, even the Panzer IV, which was far simpler and reliable than the V and VI, was also complex in its own way. Apparently even when compared to Shermans and T34s.

  • Joshua

    And people still tell us to this day we should be using the XM8……

  • DW

    What they can do to fix POI shift:
    1. Make receiver aluminum, gain weight
    2. Make barrel heavier or give it a heatsink, gain weight
    3.switch to HK416, gain weight
    tl;dr: gain weight

    • mig1nc

      I wonder if they could make the upper receiver out of the aluminum/magnesium alloy used in the BCM KMR or aluminum/lithium alloy used by Hodge Defense. Remington tested a magnesium based alloy lower receiver on the military version of the ACR.

  • mig1nc

    Ausrüstungsmix means Equipment Mix

  • JRT6

    A FI with the US Capitol Police told me about the accuracy problems 13 years ago so I’m surprised it took this long for the issue to come to head.

    • A.WChuck

      Well, this answers my speculation above. I guess CP did use them enough to see the issue.

  • Chris22lr

    How this is a news? I mean, when German army joined US in Afghanistan over 10 years ago, their SF – KSK – already reported problems with G36 melting. That was when they’ve ordered new variants of optic platform, and aluminum rail forends from KAC. From what I remember, officials state of mind was something like “yeah, SF who are actually fighting, have problems but ATM we don’t have enough cash to replace every rifle, and because grunts, who sit in barracks, are fine with them, we are fine too”.
    Fast forward to 2013, when it seems not only KSK is involved in fighting, and Bundeswehr panicks because “our guns are melting”! And HuK answers with statement such pricky as only they would do.

    BTW for American readers: some of You are wildly amazed “how come rifle is 20 years in use and nobody noticed”? Well, this is the same story with M16 and M4. Weapon works at a range and passes every test. But when in the field, under extreme weather conditions, and without proper maintenance, all the problems came out at once. For half of it’s life G36 was used mainly in barracks or at proving grounds in Germany, where weather is cold, and rules are strict. The same with M4 – great weapon in theory, while in Afghanistan and Iraq problems started to arose. But there’s already a cure: HK416, combining best of both G36 and M4. So maybe HuK’s high self-esteem have some rational basis. 🙂

    • Uniform223

      oh geez here we go again

  • Esh325

    It’s a really difficult problem as both sides have their own story. Either H&K or the German Army is not being honest about the performance of the rifles. If the design of the H&K G36 is indeed faulty in that manner, it would certainly hurt H&K’s company image and the German army may not even give them a chance to make changes to the design to fix the problem or even buy rifles from them anymore which might mean the German Army will have to look for other manufacturers to supply them with weapons.

  • tenth

    Are these the new or replaced trunnions?

    How has that any bearing on the design specifications that never called for sustained automatic fire?

  • mosinman

    T-34 track 😉

  • Brad Ferguson

    I wouldn’t fret to much…………They can switch to the HK 416, from the G 36. Chalk it up to a expensive lesson.

  • Hi my name is anonymous gunsmi

    I’ve seen these pictures at least 3-4 years ago on /k/ as well as posts debunking them.
    I know Bundeswehr guys that love it, and some that hate it and others that would just like to see the G3 back. Whether or not the G36 is crap I dont know, but I question the pictures as submitted by a “gun smith” anon.

  • Amsdorf

    It’s fun to watch the HK Fan Boys go into melt down at the thought of their precious (horribly overpriced) HK may be letting anyone down with any product.

  • FredC1968

    The G36 replaced my favorite Cold War period rifle in the service of the Bundeswehr.

  • Peter (BE)

    They should have adopted the DDR AK74 when the Wall fell….

  • John

    Gives new meaning to the MI3 movie line:

    “Ethan, there’s a G36 in the truck.”

  • sometrend

    rifle abuse! there should be jail time for offenders! lol

  • Reginald Pettifogger

    The Reuters “machine translated” report of the Bundeswehr investigation highlights why real people need to be involved in translating technical reports from one complicated language to another. What a mish-mash of gibberage.

  • H&K’s Water Cooler

    Look, this is nothing but a family squabble. OK? K never liked the damn handle on the thing. But H’s girlfriend–we call her “Yoko” around the shop–kept on about how sleek and modern it looked.

    The whole “polymer cradle” thing was K’s final “f-you” to the rifle.

    I don’t really care, but I wish “Yoko” would stop singing “Lips Like Sugar”. It’s driving us MAD.

  • Unc1852

    There are a few things that I didn’t see in the pictures. I believe that yes it is possible to get the barrel so hot that yes you can melt the polymer, shooting hundreds of rounds through the rifle without letting it cool at all you could get the barrel red hot. In a fire fight in Vietnam with soldiers carrying the M60 would sometimes change out barrels during the battle and needed special gloves to do it, because of the barrel would get so hot.
    I just see a rifle that got hot in the pictures, not how it got hot. Second I didn’t see a bunch of rifles all showing the same problem.
    I guess my point is that H&King should be allowed to join the investigation if only to show them how the rifles were tested. Soliders in a combat zone must relies on there rifles and they must work, but no rifle can withstand fully automatic rate of Fire indefinitely.
    Personally I think that it was stupid to put polymer around the barrel of a combat weapon, how could you not see this coming? I own an USP and I love it, it has never failed to cycle in the 22 years I’ve owned it. I have a feeling that H&K will fix their defective rifles, their just mad that they were left out of the loop and not allowed to correct this problem before the press was told.

  • Ted

    Anyone who owns an SL-8 has a wonderful opportunity to test the plastic-bedded trunnion theory….

  • valorius

    this is bad universal karma for hk killing the p90 pdw with NATO.

  • idahoguy101

    What rifle doesn’t lose some accuracy when it’s fired hot? They quit working all together after so many rounds. This is all assault rifles. Not just the G36

    • anonymouse

      Yes they will indeed as the metal gets warmer and flexes more from recoil, and becomes more malleable generally. Once cold they will return to normal zero. The difference is that the warping of the polymer that binds the G36’s barrel is permanent, resulting in a permanent shift in zero.