M1907/12 Schwarzlose HMG at James D Julia

The M1907/12 heavy machine gun was the standard mounted MG of the Austro-Hungarian Empire during the First World War, and saw sporadic use clear through the end of WWII. The design is unusual among heavy machine guns because it is actually an unlocked, delayed blowback system. A combination of a heavy recoil spring and significant mechanical disadvantage is used to retard the breech to the point that extraction pressure is low enough to be safe (and extraction is aided by the use of a cartridge oiler). These are definitely underappreciated guns today, being one of the most compact and simple guns of their type.

For more information on the design, and to download electronic copies of a couple original manuals, check out my Vault page on the 1907/12.


    • “being one of the most compact and simple guns of their type”
      Big difference between Schwarzlose and Maxim design was that Schwarzlose has fixed barrel, unlike Maxim, so there was not problem with sealing the water-jacket.

  1. We generally tend to look down upon machine guns that require cartridge oilers in order to extract reliably (Japanese Type 96, Italian Breda 30) as the oiled cartridges attracted dirt and when unoiled the extraction issues were usually pretty brutal to clear (stuck casings, torn rims, both) but I get the impression based on how Ian talks about it on the Schwarzlose that it wasn’t as much of a problem in this case.

    Seeing as I know next to nothing about this particular MG other than the fact that they seemed to have worked well enough to survive WW1 trench warfare, what made the 1907 better?

    • I don’t think a requirement for an integrated cartridge oiler was a huge deal if the weapon was otherwise a sound design. Admittedly it was one more consumable which can run out at a critical moment, so it that regard it added unnecessary complexity to the gun. The Schwarzlose MG was not the only machine gun which worked more or less reliably with an integrated oiler; the Fiat-Revelli M1914 and Breda M1937 & M1938 were sufficiently reliable as well.

      It is notable that the biggest problems with cartridge oiling were related to either very open design (Type 11 LMG) or actually pre-oiled cartridges such as in the Type 96 LMG and the Fiat M1935 HMG (which was originally not supposed to need oiled cartridges, but ended up needing them anyways, since the fluted chamber design didn’t work properly). In those gases the oil gathered sand and dirt easily. Guns with an integral oiler and closed designs tended to work better, because the cartridge case was oiled only just before firing.

    • According to George Chinn, the various iterations of the Oerlikon/Buhrle 20mm cannon (Oerlikon AA, Hispano, British Hispano, AN-M2/M3, etc.) all required some form of lubrication of the cartridges, ranging from coating them with a thin film of oil during the belt-loading process, to a form of “paste wax” applied at the factory to some lots intended for USN service during WW2. Most high-power blowback system weapons share this attribute.

      As long as they function reliably, it probably doesn’t make that much difference in the real world. Although I suspect at least a few of them would have worked just as well with a fluted chamber instead of lubricated cartridge cases.



      • Eon, I don’t know why you still insist that the 20mm Hispano and AN-M2/M3 belonged to the Becker/Oerlikon API Blowback family of guns. They didn’t, since they were gas operated. Chinn himself describes the operation of the Hispano thus (page 566):

        The gun is now in the cocked bolt position and release of the sear allows the driving spring to force the bolt and its components forward. As the front face of the bolt passes under the rear of the feed mouth, it engages the rim of the cartridge, forcing it down into the extractor claws, and continues to push it towards the chamber. Continued travel completes the seating of the cartridge and the forward motion of the bolt is finally stopped by contact with the barrel and receiver. At the instant of impact the breechblock lock is cammed downward into locked position against its locking key, held securely by the continued travel of the slides.

        The latter, which are connected through the bolt body by means of a key that carries the firing pin, are now driven on by the combined action of the breechblock-slide springs and the inertia of the entire assembly, causing the firing pin to strike the primer. The powder charge in the cartridge is thereby ignited. The bolt is positively locked at the instant of firing and remains that way until the projectile has passed the port in the barrel, at which point gas is bled into the cylinder that houses the actuating piston.”

        Now, that is nothing like API blowback. It did require lubricated cartridges, but not because the action was blowback.

  2. Isn’t that the original DShk model 1938 also have a rotary feed? That was ditched by the end of WWII for a simpler feed tray design by Shpagin.

    • Hi Tim,

      No need to seek that far as early Dushka – just take a look at the M134 Minigun with its Feeder-Delinker assembly: it also strips the rounds from the links while rotating, and it is even closer to the Schwarz in feeding the rounds UP into the gun.

  3. Master Schwarzlose also invented the very best early automatic pistol, the Standart Model 1898! Quite an accomplished designer-engineer!

  4. Well, for an unappreciated gun today, the Schwarzlose was one of the most popular water-cooled machine guns of its heyday. It was simple and easy to build compared to the Maxim gun and fairly reliable well after World War One despite low muzzle velocity and short range (range wouldn’t matter too much if you use the terrain correctly.) Mitigating the range issue would be a matter of placing the Schwarzlose guns in areas difficult to sprint across and where most “leap-frogging” attackers would get stuck in the mud (or if you’re evil enough, have overconfident attackers unknowingly tumble into pitfall traps with spikes at the bottom). Considering how well built this gun is (and probably as idiot-proof as the Vickers), it is no surprise that it served well into the 1980’s in some obscure locations.

    • “low muzzle velocity and short range”
      The http://www.hungariae.com/Schwarz.htm states that Austrian (8x50R Mannlicher) Schwarzlose machine-gun has sights scalled up to 1800 meters, however i don’t know how it works in real conditions. I think that “low muzzle and short range” was caused by the cartridge used (8x50R Mannlicher) not the design of machine-gun – the Schwarzlose was also produced in other cartridge variants – 6.5mm for Netherlands, in Czechoslovakia Schwarzlose machine-guns was rebuild to fire 7.92x57mm Mauser cartridge.

    • Especially in World War I, short range is a disadvantage in HMGs as it limits their ability to perform indirect fire, although the Schwarzlose isn’t set up for that in the first place.

  5. I have read some where that Schwarzlose machine gun cannot be synchronized for air combat use relating to the delay blow back design. Seems to make sense, due to the firing rate is directly related to the variation of the cartridge powder charge.

    • Synchronizing a machine gun to the propeller pretty much required a recoil operating system when conventional percussion primed ammo was used. That is why the French fighters in WW1 used British Vickers guns when synchronization was needed. With electric primers synchronizing is easier and would probably have been possible with gas-operated guns, but electric primers started to become more common only after WW2 in the jet age, when synchronization was no longer needed. The German WW2 MG131 used electric primers, but the gun was still recoil-operated.

      • “With electric primers synchronizing is easier and would probably have been possible with gas-operated guns”
        It is possible to synchronize gas-operated machine-gun without electric primers – the Soviet Berezin 12.7mm machine gun in its synchronized version called UBS (standing for Universal, Berezin, Synchronous) was used in many Soviet fighters including: I-15, I-16 Type 29, YaK-1b, YaK-3, YaK-7b, YaK-9, MiG-3, LaGG-3. The Berezin UB fires standard 12.7×108 (DShK) ammunition, the rate-of-fire for UBS is 700-800rpm (unsynchronized UBT (Universal, Berezin, Turret) has RoF 1000rpm)

        • Quite right, I totally forgot about the UB and the fact that it was gas-operated. However, it is notable that the synchronization reduced rate of fire considerably.

          • Yeah, and ditto for ShKAS in 7.62x54R which was a predecessor of 12.7 mm synchronized weapons in Soviet fighters as of 1936.

    • It’s great that isn’t it, I watched it awhile ago… Have you seen that 3 barreled Hotchkiss cannon, I reckon you could use that’ish in conjunction with this belt feed mechanism and a cylinder that counter rotates in 45/50… Bulldog Gatling winder job, did a picture of it the barrels fit into a Lewis gun shroud. It was quite complicated to draw but I reckon it might work, cheaper than six barrels.

      Just thinking of modern gatling ideas, laws etc. It had six cylinders, what’s that thing called… A ratchet? It was geared to slip on rotation of the cylinder per barrel rotation, er aye it fired six through one barrel then the next etc. I am sure I had it worked out eventually, load eject fire, the barrels went one way the cylinder the other.

      • Actually it had two strikers, so that can’t be right… Must have fired two simultaneously, got the picture have to have another look probably needs more work yawn he he.

  6. Interestingly, all intriqued delay blowback systems are described within magic word, “Mechanical Disadvantage”. However, in this case it becomes by the fact that the hinge point at middle of toggle joint at fully opened form locates at the foremost of action as folded over the breech when closed situation, and begins to open as carrying its mass by draft of rearmost hinge point connected to the breechbolt, through an upward arc as crossing backward considerably long distance to reach to nearly upward position, at where, the front face of breechbolt seperates slightly from the breech within the same time.

  7. One of the reasons why it’s so compact is that the operating mechanism REQUIRES a short barrel to prevent the action from opening with a bullet in the barrel.

    • Like the Remington R51 as is my understanding via a Russian fellow on here, it’s short barrel is integral to the design in order for it to function… Is that right?

        • Should be quite right. Longer barrels, generaly do not wait detay mechanism’s balanced action. However, it also can be adjusted by changing mass values but in this case, compactness may be lost.

    • No, it doesn’t necessarily require a short barrel. The interwar Czech conversion in 7.92x57mm had a significantly longer barrel and the Dutch 6.5mm version had a longer barrel as well. It is likely that Schwarzlose chose the short barrel primarily to keep the weight of the gun down; like Strongarm wrote below, increasing the barrel length would have required “beefing up” other parts of the action as well.

      • As they say, there’s no such thing as a free lunch. Lengthen the barrel and you have to make changes elsewhere as well.

        • Czech vz.07/12/24 and 07/24 had longer barrels and worked just fine. Actually it was most reliable machinegun available to Yugoslavia in late 1920s, and that is something when competition is Maxim MG-08 and Hotchkiss…

  8. Can anybody enlighten me regarding Dutch chamberings for these guns?

    I once read something (forget where, Hogg???) that implied that at least some of the Dutch guns were chambered for 7.92x57mmR, or something similar. In my casual research on this, I haven’t been able to find an actual reference to this.

    Is this true, or did I just misinterpret somebody’s ambiguous statement?

    • Dutch Schwarzloses were chambered in actually two calibers: 6.5x54R (up until 1925) and 7.9x57R (1925-1940). There were actually 3 or 4 different models of Schwarzlose MGs in the Dutch service, starting with M.08 (a Dutch’d up version of the MG M.7, with RoF of 350 rpm), replaced by a short series of M.08/13 (a Dutch equivalent of M.07/12, RoF 400 rpm), and after the WW1 started the Steyr could not spare production facilities to supply the guns to neutral Netherlands, and so the Dutch opened up manufacturing of their own slightly improved version in Hembrug, under the designation of M.08/15 (RoF 450 rpm) – not to be mistaken with the German MG 08/15, with which it had nothing in common whatsoever. A propos the short barrel being ‘mandatory’ in Schwarzloses, all Dutch guns had 700 mm barrels – only the 1917-introduced special Cavallerie-Mitrailleur (all 118 + 101 of similar but 1 kilo heavier Gew.Mod.) had an Austrian-sized 525-mm bbl to reduce weight for cavalry support role. These were chambered for the Dutch Mannlicher 6.5x54R, using mainly Scherpe Patroon No.1M and No.9 ball. As of 1925 the new round 7.9x57R being for all practical purposes the 7.9 mm German round with a rimmed case replaced the 6.5 mm for machine guns, and most existing MGs in the army (M.08, 08/13, 08/15, Cav.Mitr, Gew.Mod. Schwarzloses, M.18 Vickers, M.20 Lewis and M.25 German MG 08 Maxims) were gradually being re-calibered for the new round, while the newly-manufactured guns were already chambered in it, using the Scherpe Patroon No.23. Also the Air Force Brownings, the M.36, were chambered for the 7.9 mm, and special No.23L (Lichtspoor, tracer) and No.23P (Pantser, AP) ammunition was used alongside the No.23 ball. What may be interesting is that all MGs used ONLY 6.5 mm blanks (Loose Patroon No.8), except M.36s, which fired no blanks at all. Thus going blank you only slapped a BFA on muzzle, but actually changed the whole barrel to one that could not chamber a live cartridge from a live belt loaded into the gun by mistake (unless one mixed infantry rifle 6.5 mm rounds in to the blank belt, which would hardly be a mistake…).

      • “going blank you only slapped a BFA on muzzle” – I meant “going blank you NOT only slapped a BFA on muzzle”,

        sorry, my mistake

      • That’s a lot of useful information. Thanks.

        Do you know if the Dutch 7.92x57mmR case is dimensionally close enough to commercial 7.92x57mmR to be used in (typically) drillings, double rifles and single shot hunting rifles (and vice versa)? Obviously that would depend upon shoulder position and angle, neck length, etc.

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