August Coenders’ 9x19mm Belt-Fed MG

August Coenders was an independent arms designer in Germany. During the 1930s he spent several years working in England and at the French Puteaux Arsenal, which contributed to a general lack of trust and interest in his designs by the German high command (the man’s generally adversarial nature didn’t help either). He developed several different types of gun during World War Two, including a belt-fed 8mm machine gun, a last ditch Volkssturm bolt action rifle, and this 9x19mm Parabellum caliber belt fed machine gun.

This 9mm belt-fed was probably intended for use as a vehicle machine gun, where the range and power of the ammunition was not really a liability, and where the compact nature of the gun and its ammunition would be a real advantage. The German military was not interested in it, though, and this gun was captured by American troops at the end of the war, missing its barrel and feed cover. It was taken back to Aberdeen Proving Grounds for examination, where a new barrel and an MG42-type feed cover were fabricated for it.

Today it resides in a Maltese private collection, where I had the opportunity to film it thanks to the Association of Maltese Arms Collectors and Shooters.



  1. I can’t imagine how any infantryman would be dumb enough to joust a tank. By joust I mean charge head-on with a rocket launcher or with a magnetic mine…

  2. The basic concept (according to Aberdeen) seems to be similar to that of the later American M231 Firing Port Weapon;


    The original barrel and sight assembly, plus that complex top cover, make me think otherwise.

    I strongly suspect this was intended at least initially as a Volkssturm weapon. The concept would seem to be for a SAW that fired 9 x 19mm pistol ammunition instead of a rifle round.

    The logic behind it would be that;

    1. A straight blowback weapon would be simpler and cheaper to make than any sort of locked-breech or delayed-blowback full-auto weapon,in Germany’s rapidly collapsing industrial base condition in 1945.

    2. It would be faster and easier to train what were essentially civilians to use and maintain; note the very simple stripping procedure, much less involved than even the MG15.

    3. 9 x 19mm pistol ammunition was probably available in greater quantities (and more easily accessible in all parts of the country) than rifle-caliber ammunition.

    4. At MOBUA ranges, 9 x 19mm was a perfectly adequate man-killer, which was what was needed with the Red Army coming over the hill.


    5. Even a pistol-caliber SAW was better than the infantry having no support LMG at all. Which even with the Wehrmacht was often the case at that point (spring of ’45).

    I suspect the buffer in the bolt was intended to reduce both recoil and RoF. The apparent presence of a rotary feed belt-transport indicates that a fairly high RoF was envisioned, probably around 800-900 R/M- which incidentally tends to militate against its use as a “normal” SMG, the Russian PPSh-41 notwithstanding. Without the buffer, the RoF would probably have been over 1,200 R/M, resulting in a virtually uncontrollable weapon.

    In many ways, it’s almost a reversion to the original WW1 Italian Villar Perosa 9mm twin mount gun system, which of course was intended as an observer’s flexible aircraft gun. But the Luftwaffe would have had no use for a pistol-caliber aircraft gun, and at that point the main user of their MG15 flexible guns was…the Wehrmacht and Volkssturm, as they had very few usable aircraft left, and almost no fuel for what they did have.

    I’m going to say that this was another “last-ditch” weapon, intended to arm the “People’s Army” in the dying days of the Reich.




    • “But the Luftwaffe would have had no use for a pistol-caliber aircraft gun, and at that point the main user of their MG15 flexible guns was…the Wehrmacht and Volkssturm, as they had very few usable aircraft left, and almost no fuel for what they did have.”
      Here I must note actually Luftwaffe was part of Wehrmacht.

    • The problem I have with the Volkssturm theory is that even a 9mm Parabellum “LMG” with a belt feed seems a little expensive for a Volkssturm last ditch weapon. It required a proprietary belt design, whereas all other last ditch weapons were designed to use existing magazines if a detachable magazine was envisioned. Furthermore, even the gun itself would have probably been at least as expensive to make as an MP 40, which the Germans usually did not give to Volkssturm units. It also lacked a bipod (as far as we know), which would have been needed for LMG like operation on a prone shooting position. Without a bipod the belt feed appears superfluous for a pure infantry weapon.

      • If you check the link listed below (which I didn’t see until after i’d posted), it claims that the weapon was actually 7.9 x 33mm Kurz caliber, not 9 x 19mm.

        If so, it could use the standard links for the MG34 or MG42, as they were designed for the same case head diameter as the Kurz round.

        If it was in fact originally built for the Kurz assault rifle round, that would tend to be an even better explanation for the buffer spring assembly in the bolt. To retard bolt opening until pressure in the chamber and barrel had dropped to a safe enough level for extraction without risking case failures.

        I’d definitely like to apply some micrometers to that bolt face and extractor, just to determine if it really is a 9mm dimensioned setup or one for 7.9. I am now tending to suspect the latter. In short, Aberdeen goofed back in ’45.

        A 9mm SAW might not make a lot of sense, but one in 7.9 x 33mm would be a horse of a different color, especially in street fighting. Who needs a SAW with an effective range of over 800 meters when you can only see (or shoot) for about 150 to 200 to begin with, because there are buildings in the way?



  3. “August Coenders”
    I searched for him and it looks that (english) wikipedia has very rudimentary data about him:
    One photo of Coenders himself and some of his weapons might are there:
    2nd photo from top shows: two guns for Volksturm, belt-fed sub-machine gun erroneously described as firing 7,92×33 cartridge instead of 9×19 Parabellum, 7,92×57 machine gun, Coenders’s helper said it was able to fire 2200-2400 rpm. Both third and fourth have quick change barrel
    4th photo from top shows testing of 7,92×57 machine gun, belt is hold by Friedrich Anschütz
    6th photo: shows belt-fed sub-machine gun together with links.
    It said that during war he worked for Röchling’sche Eisen und Stahlwerke GmbH.
    In 1944 he was awarded Dr.-Fritz-Todt-Preis for developments in artillery systems area. After war, till death, he lived in Düsseldorf. In 1957 he got US patent for lighter.

    • I believe we had touch on him in past at FW. He was well rounded and advanturous man for sure. His international experience proved to be hurdle instead of benefit.
      This sample of his work is a lesson of universality in thought and simplicity of practical design conduct. I am also inclined to believe it was intended for vehicular use.

    • The Volksturm rifle with a rotating barrel locking mechanism is very interesting and shows “out of the box” thinking. While the accuracy of such a system would probably not be very good, it may very well be the cheapest way to build a manually repeating rifle.

  4. “This 9mm belt-fed was probably intended for use as a vehicle machine gun”
    I doubt in that. Germans responsible for tank development, seems to be content with tank version of MG 34 already in service. There I want to note, that according to TM 9-721 vehicle known as HEAVY TANKS M6 AND M6A1 have as part of Armament:
    GUN, Thompson, submachine, cal. .45, M1928A1, one in front right-hand sponson and one in turret. Ammunition carried for these weapons was 1200 rounds. Notice that it was ready sub-machine gun, rather than special weapon and that while using sub-machine gun as tank weapon might allow some space and weight saving, these will be most probably negligible – after all what is few kg when we are talking about vehicles weighting few tens of tons*?
    In Soviet Union belt-fed sub-machine gun was also created (7,62×25 cartridge), see photo:
    it was supposed to be used in way similar to DP light machine gun.

    * metric

    • Just so you are aware the M6 including A1 variant never got approved for service or passed trials. Anything in reference to it is purely hypothetical. The U.S. did not field a heavy tank since they found it hard to make one as reliably and efficient as the medium tanks.

  5. While I find eon’s theory plausible, I still think that this weapon was intended to be used as a hull machine gun of tanks. The hull gunner usually had quite limited field of view and simple low power optics (if any at all) for aiming the gun. That limited the practical range of hull machine guns. Usually they were used for engaging infantry stupid or desparate enough to move cross the frontal arc of the tank or for “reconnaissance by fire”, that is, shooting a burst at suspected infantry hiding places. For such use 9mm Parabellum would usually be good enough. In addition the gun could be made easily detachable, which would provide the crew significant increase in defensive firepower if they ever had to leave the tank on the battlefield.

    There is also a precedent for a 9mm Parabellum weapon used as a hull machine gun, namely the tank version of the Suomi designed for Vickers 6-ton tanks. It could also be quickly detached and used for protecting the crew after leaving the tank or for all-round defense from the top hatch (the tanks had no AAMG). Although Coenders probably did not know about the tank version of the Suomi, it is quite possible that he had similar ideas. I actually wouldn’t be surprised if the original feed mechanism even included an option to feed from MP 40 magazines for detached use in addition to belts.

    • “gun could be made easily detachable” suggest that tank variant of MG 34 could be used as stand-alone weapon: kit for quick conversion to ground use was carried inside the tank containing a butt-stock and a combined bi-pod and front sight assembly
      I am far from believing wikipedia without any doubts, so I hope someone could check it against German tank manuals or alternatively point time-period photo showing tank MG 34 in “out of tank” use.

      “tank version of the Suomi designed for Vickers 6-ton tanks”
      But, wasn’t it first tank machine gun produced in Finland? When in Coenders case it would mean switch from already used MG34Panzerlauf to ballistic-wise inferior weapon, but which anyway needs similar orifice in armour, which mean potential weak place.

    • “I actually wouldn’t be surprised if the original feed mechanism even included an option to feed from MP 40 magazines for detached use in addition to belts.”
      Wasn’t German tankers already equipped with MP 40 at that point of war?

      • Yes, but typically only one per tank, I believe. As for the MG 34 ground conversion kit, I think Wikipedia is correct despite lacking references for that piece of information. However, the MG 34 is not a very good defensive weapon for a tank crew moving on foot. It could not be fired from the shoulder and while firing from the hip with a sling was possible and taught to infantry, I doubt the tank crewmembers would have been very adept at it even if they actually had the requisite sling. It was also a fairly heavy and long weapon and as such difficult to extract from a cramped tanka and especially from the hull MG position.

  6. [off-topic so ignore if you wish]
    So far I only found following:
    this article [Russian]: has short mention and one photo (8th image from top), it only say that ZK 477 was 12,7 mm machine gun considered as AA weapon for Czechoslovak tanks designed in postwar era.
    this article [Czech]: mention in once in context of adopting (for license-production) Soviet DShKM, it says as follows:
    Na poradě v listopadu 1947 začali vojáci poprvé uvažovat i o velkorážovém kulometu, nejlépe ráže 12,7 mm, přičemž se preferovala protiletadlová střelba (střelba na pozemní cíle se považovala za vedlejší); ke skutečné objednávce ale došlo až koncem roku 1948. Jednalo se jednak o typ ZK 477 s krátkým zákluzem hlavně a pístovým mechanizmem, jednak o vývoj typu ZK 483 na principu zákluzu hlavně. V roce 1949 pak zadalo MNO (už nově vzniklé Konstruktě) také řešení a vývoj kulometu ráže 12,7 mm o vysokém výkonu ZK 496 (vývoj ale byl v únoru 1950 zase zastaven). A v roce 1951 byl nakonec schválen do výzbroje československé armády a zaveden do licenční výroby sovětský 12,7mm kulomet vz. 38/46 (modernizovaný DŠK), v roce 1953 pak čtyřkulomet ráže 12,7 mm na domácí lafetě.
    Which means that, if I understand it correctly enough:
    In 1947 [Czechoslovak] forces start searching heavy (literally: big caliber) machine gun, preferably 12,7 mm [does this mean 12,7×108 Soviet cartridge or something different?], which would be used mainly as anti-aircraft weapon. Actual request was done 1948. There were proposed ZK 477 using short-recoil [part I do not understand] principle and ZK 483 using recoiling barrel principle[???]. In 1949 MNO requested development of 12,7 mm high-power [what does that mean?] machine gun with codename ZK 496. Development of this weapon ceased [due to…?] in February 1950. In 1951 DShKM (license produced version) was accepted for service. In 1953 domestically developed quadruple mount for DShKM was accepted.

    Fact of placing this data there suggest that there exist some link between Josef Koucký and ZK 477.

  7. Russians ran a program for a 7.62×25 machine gun known as LAD. However, their intent was to provide something akin to the future RPD or (far future) SAW. They recognized that DPM was not adequate and wanted a greater volume of fire. Also, the Central Department of Armament required the new MG to have half machine time of DP to make. The LAD was relatively well developed until the shift to intermidiate cartridge killed the program abruptly in 1943.

    This article has pictures:

      • “That butstock looks like suited for much larger weapon.”
        It was supposed to be used similarly to DP, see photo showing firing from prone position.

  8. I’m still wondering about the absurdity of designing for a proprietary, non disintegrating, metal belt for Parabellum. What facility did Coenders have to make such a thing? Was it adapted from some existing stock?

    And what did the guy who stole it hope to DO with it?

    • “What facility did Coenders have to make such a thing?”
      During World War II Coenders was working in design bureau of Röchling’sche Eisen und Stahlwerke GmbH, one man working with him claim, that boss of this entity consider Coenders to be genius.

  9. I think that the gun was originally made with a curved barrel and used with a ball mount to stop enemy soldiers attaching magnetic mines to the tank.
    The new barrel and feed cover was made in the 1980`s by Henk Visser`s workmen and as finished it was mounted in a ball mount.Do you know how the 13 round section of belt was stolen ?

  10. This gun might be considered a delayed/retarded blowback gun. Neither the bolt nor the recoil spring seem that impressive. During the main portion of recoil/counter recoil the bolt is slowed by the belt feed mechanism. That brings up a question of how much belt will this pull before malfunctioning? Presumably it could be designed with the cam track to turn the spindle providing extra delay at bolt opening. Another thing to consider is that the bolt must have sufficient momentum to overcome the push through belt during the feeding cycle.

  11. That 1930s vogue for 9x19mm squad automatics comes to mind, but surely Coenders wasn’t thinking on those lines. I suspect that Volkssturm-level was what he intended, plus possible use as a ball-mounted tank defensive weapon also, with a Krummlauf attachment for giggles.

  12. There appeared to be something interesting going on with the trigger and T-shaped spring behind the grip. Was that a safety mechanism of some kind?

  13. In addition to the bolt-handle-reciprocating-barrel 8x57mm manual repeater prototype, Coenders also designed a five-shot self-loading repeating carbine in the 7.92x33mm kurz cartridge. That one used (well, if it worked at all?) a blow-forward system.
    The front muzzle had a sort of muzzle-brake looking arrangement that was grasped and pulled forward against the pressure of a return spring, and then rotated to hold it in a locked forward state. Then a five-round charger was inserted into the open loading/ejectiong port, the cartridges thumbed down into a simple fixed magazine, the empty stripper clip removed, and then the barrel pulled a bit forward and rotated back so the spring could assert pressure, forcing the entire barrel back and in so doing, stripping off the top round of the magazine and chambering it. It had a simple/rudimentary double-action-only trigger that fired the round. No idea if actually worked as a self-loading rifled or not.

    Карабин Coenders-Röchling Volkssturmkarabiner

    • This 7.92×33 semi auto is not a bad idea, it adds the barrel mass to the whole blowback (I suppose) system.

      If it works reliably, is a good question!

      I really hope Ian would do, one day, videos on both these very interesting conceptual weapons.

  14. Coenders was the designer behind the multi-chamber Hochdruckpumpe (also known as V3) long range cannon that was installed in the Mimoyecques underground site.
    He had no knowledge in supersonic aerodynamics and his fin-stabilized projectile design did not work. It had to be corrected by others.

  15. It looks like a gun which arrived at least one war too early

    Myears Father’s contemporaries got conscripted into the Korean war

    Sorry, “police action”

    Where tank crews ended up hosing down the adjacent tanks with machine gun fire, to remove the accumulated mass of human bodies that were clinging to them.

    People who were engaged as mechanics, complained about the volume of human body parts that were stuck to every part of any armoured vehicle that came in for maintenance.

  16. very interesting that they made a weapon for this very purpose, mp40 does have a “port device” below its muzzle.

    • More like “edge device”. It was intended to be used on the side panels of trucks and half-tracks, which were all open-topped. The Germans had no mass-produced APCs with a fully enclosed space for dismounts. The modern enclosed APC was invented during the war by Western Allies, originally as a mean to utilize obsolescent tank chassis.

  17. Ooh, silly thought:
    One of the weirder planes used by the Luftwaffe was a DFS Habicht sailplane with an MP40 in the nose; supposedly as a cheap option for basic gunnery training.

    Note that the magazine stuck out the side of the plane – a belt fed SMG would have allowed a cleaner installation (and also more ammunition).

    Thus I propose that this weapon was intended for installation in a training aircraft, with a secondary purpose as an individual weapon

  18. Not really an original thought here, but I tend to agree with what others like eon and Denny have already stated, that it looks like a simple, late war, limited resources production, APC weapon. And 9mm does seem much less plausible than 7.92 Kurz, especially if additional mfg technique was required to fab 9mm belt links. It’s possible the Kurz rounds were still available in some quantities, at least enough to consider the option of mfg.

    But given his other work on Volksturm weapons, maybe the design was just playing into current late war eventuality and this was just a “poor man’s MG42” so to speak. Given that other last ditch weapons shared that caliber, it is a feasible concept. The crudeness of design lends itself toward that argument as well. The grip and buttstock bear this out.

    One interesting thought, though. Imagine if somehow one of the only surviving examples of Stoners work was an M231 port gun, how would history rank his skills? Or alternatively, it would be intetesting to see how a heavy barrel infantry LMG in 7.92K would do, if properly equipped and kitted out. It is amazing how simple, yet effective, this design may have been, if produced in quantity.

  19. I have to disagree, while compactness is important for a internally mounted tank MG, its short range and poor penetration cannot be scarified. WWII tank coaxial and bow MGs were extremely important weapons, often considered minor weapons compared to the large-caliber main guns. However, tankers know they are critical not only for close-in defense as many believe that is their main role, but they are essential offensive weapons mainly for suppressive fire and knocking out enemy MG and AT gun positions. They need at least immediate range and effective penetration. AT gun shield thickness was determined by the estimated engagement range of enemy tank MGs. This particular weapon was devised only as a close-defense weapon and was ineffective as offensive weapon. To obtain a few inches in spacing saving it sacrificed one of the tank’s main weapons.

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