Roth-Sauer Automatic Pistol at RIA

The Roth-Sauer is a rare early automatic pistol designed by Karel Krnka, financed by Georg Roth, and manufactured by J.P. Sauer & Sohn in Germany. It is mechanically quite complex – much moreso than strictly necessary. The action is a long-recoil type, in which the bolt and barrel remain locked together through the full rearward travel of the bolt. The bolt then stays to the rear while the barrel recoils forward, clears the empty case, and ejects it. Once the barrel is fully forward, the bolt is released to strip a new cartridge from the magazine and chamber it. The bolt has a single locking lug, which rotates into a recess in the barrel extension to lock.

The firing mechanism on the Roth-Sauer is very similar to the later Roth-Steyr 1907 pistol – and to the modern style of the Glock and others. It uses a striker to fire, which is tensioned to half-cock by the bolt and barrel recoiling with each shot. Full tension on the striker is delivered by the trigger pull, resulting in a approximation of a double-action system. Very much ahead of its day. The Roth-Sauer is chambered for the 7.65mm Roth-Sauer cartridge, which uses a 13mm-long case and it practically identical to the short 7.65mm Frommer (the pistol also shares characteristics with Frommer pistols, as Roth was involved with both designers). It is a quite light cartridge, propelling a 71 grain bullet at 820 fps.



  1. If the pistol had been chambered for .32 ACP (7.65 x 17SR), it might have survived.

    It looks like Krnka was trying to design a self-loading pistol that was nearly as failure-proof (and/or “idiot-proof”) as a double-action revolver, and in large part he succeeded. You obviously have to really want to fire this one to make it go off. Only a grip safety would have made it more secure.

    Speaking of security, the system could obviously handle more intense pressures and therefore higher-powered rounds. Consider Hugh Gabbett-Fairfax’s “Mars” long-recoil autopistols, which fired rounds with ballistics well up into what we consider the Magnum range today. According to tests at the Royal Small Arms Factory (Enfield) in 1901, his .450 launched a 216-grain bullet at 1,140 FPS, yielding 624 FPE, equivalent to a “warm” .41 Magnum or a genuinely “hot” .357 Magnum load of today.

    The Mars pistol’s main drawbacks, of course, were mechanical fragility and its massive recoil. Two problems the Roth-Sauer apparently didn’t have.

    The stripper-clip loading system really isn’t that big a handicap for what is basically a pocket pistol. Not having a detachable magazine equals one less thing to lose, and the mechanism is always enclosed, protecting it from invasion by foreign matter (dirt, pocket lint, savage dust bunnies, etc.). A couple of spare stripper clips could easily have been tucked into the watch pocket behind one’s pocket watch. In fact, this is probably exactly how its owner in Capetown carried this pistol.

    If it were available in an easily-obtainable caliber today, I’d consider it as a carry pistol. One in something like 7.65 x 17SR, or even 7.65 x 22 (.30 Luger) would be highly interesting.



    • Speaking of idiot-proofing the Roth-Sauer, it is also a gun a bad guy can’t put out of action by grabbing the frame while you’re drawing a bead on his left temple. Most modern semi-automatic pistols can be disabled by having their slides put out of battery (the Glock might be an exception). Similarly, revolvers can’t shoot if you block the hammer or somehow manage to damage the cylinder or prevent it from rotating.

      So let’s imagine what would happen if I were an army officer with this as my sidearm and some unruly thug were to attempt to push me into a dark alley. I draw the Roth-Sauer, rack the bolt and draw a bead on the thug. The thug, not knowing what I have in my hand, grabs the gun thinking it’s likely a Colt Model 1903 Hammerless. The thug then loses his hand. Would anyone want to lend me a hand in correcting this if I’m wrong (no, I will not shoot your hand)?

      • No, you’re not.

        The Roth-Sauer’s contemporaries, the Frommer 1906 and 1910, and the Frommer “Stop” and its subcompact rendition, the “Baby”, also had such an arrangement. The “Stop” and “Baby” look very different from the rest, because their setup houses both recoil springs (the barrel spring up front, the bolt spring aft) in the same tube atop the barrel/bolt housing proper;

        The German Mann .25 auto of 1921 vintage had a very similar arrangement;

        It was noted for “biting” the shooter’s hand with that bolt-retraction block, and was never too popular. It’s consequently rare today.

        The later Whitney “Wolverine” .22 auto had a similar setup. The Ruger .22 automatic has a roughly analogous structure, as did the big AMP AutoMag designed by Max Gera, and its “ancestor”, the Grant Hammond .45 pistol entered by High Standard in the 1909 Army Pistol Trials.

        The only way to stop any of these from firing would really be to grab the gun as far aft as possible and shove the bolt back out of battery. Frankly, taking the gun away from its rightful owner would probably be a lot simpler.

        You might grab it and put your palm over the ejection port, thereby smokestacking the ejected case on the first shot. But that still means the shooter is going to get at least one shot off, and it’s pointed at you.

        I’d say the best way not to get shot with any of these is like any other defensive pistol. Don’t attack whoever is holding it.



    • “One in something like 7.65 x 17SR, or even 7.65 x 22 (.30 Luger) would be highly interesting.” states that: “Roth Sauer (…) Chambering: 7.65x17mm Roth-Sauer Auto”
      Can you point the source of: “The Roth-Sauer is chambered for the 7.65mm Roth-Sauer cartridge, which uses a 13mm-long case and it practically identical to the short 7.65mm Frommer”?

      • On the other hand, according to municion article about 7.65 Roth-Sauer:
        “El cartucho es muy parecido al 7.65×13 SR Frommer, pero éste es ligeramente más grueso y con una pequeña pestaña (Semi rimmed). Son incompatibles.”
        Which I understand like: 7.65×13 Roth Sauer was developed from 7.65×13 SR Frommer, but there 2 cartridge are not interchangeable because Roth-Sauer is rimless when Frommer is semi-rimmed. If I understand this incorrectly please correct me (I use translator – I don’t know Spanish).

        • None of my references even mentions these cartridges. Ezell, in Handguns of the World, describes the pistols and their history but neglects to mention that their 7.65mm round is not the same as the 7.65x17SR Browning aka .32 ACP. The Frommer Model 1910 and “Stop” were chambered for .32 ACP, so it’s entirely possible that Ezell simply did not know there was a difference.

          The Austrians seem to have had the same preoccupation that the later Soviet system did, i.e. chambering their small arms for “proprietary” cartridges nobody else used, the Frommer pistols being the exception to the rule. The Model 1900 Mannlicher automatic, for instance, uses a 7.63 x 27.5mm rimless, straight-walled round rather like the French 7.65 x 20mm round for the MAS Model 1935A and 1935S pistols and the MAS 38 SMG.

          The French round (apparently based on the American WW1 experimental .30 Pedersen round for the Pedersen Device) fired a 90-grain bullet at 985 FPS for 194 FPE (about the energy of a .38 S&W revolver with the U.S. standard 145-grain bullet commercial load).

          The Austrian round launched an 85-grain bullet at 1,000 FPS exactly for 189 FPE. The five foot-pound difference wouldn’t pay the recipient’s burial expenses, IMHO. And neither one was much of an improvement over the standard .32 ACP (77 grain @ 1,000 FPS for 171 FPE).

          In fact, the Austrians and French could have chambered all their service and commercial 7.65mm- bored pistols for .32 ACP, gotten about the same results, and saved themselves and everyone else a lot of aggravation.

          Oh well, that’s bureaucracy for you.



          • As I think have written here before, those numbers for the 7.65mm Long are quite low. The lowest load numbers in French sources I have seen are 90 grains at 1017 fps for 207 ft-lbf. The most common are 85 grains at 1,120 fps for 231 ft-lbf, which was almost certainly the French military load. Both with the MAS Mle 1935A pistol. Both are a good deal more powerful than contemporary .32 ACP loads and even the weaker one is similar to typical .380 ACP loads.

          • R.L. Wilson’s “Textbook of Automatic Pistols” includes the 7.65 Roth-Sauer. I think the Frommer confusion comes from the fact that the Stop appears to have been designed for a slightly hotter version of the .32ACP, which was also called 7.65mm Frommer despite being about 4mm longer than the previous 7.65mm Frommer. Stops will usually run on normal .32ACP, so the original chambering has been generally forgotten.

  2. This pistol carries lots of arcane features (in terms of structure and appearance) which would be unacceptable to mimic from cost point of view today. That is what makes them so attractive, I suppose. Similarly as Frommer it carries lots of built-in ingenuity.

    This is history at its best!

  3. Krnka was actually Bohemian (czech). Though, he was born in Romania – dont ask me how is that, his father was czech nationality too…

    • “his father was czech nationality too”
      And was firearm-inventor too. Sylvestr Krnka (1825-1903) was working on conversion of muzzle-loading rifle to breech-loading. In 1849 he converted Augustin Model 1842 rifle to use paper-cartridge. It was tested in 1850 in Prague and the result was positive but Artillery Committee in Vienna reject this design. In 1854 he designed new hard lead bullet and new HE shell type. In 1855 after analyze of Crimean War he start developing rifled barrel and paper or metallic cartridge, in 1856 he publish effect of his work. In this same year the new rifle was tested but it was rejected. Despite this was still working on his design 1 March 1867 he got patent for his firearm: Austrian Patent Number 36679/497. His rifle was rejected by Austria but adopted by Russia (M1867 Russian Krnka) and Montenegro. In 1874 he got patent for “automatic rifle”, year later “small-calibre breech-loading rifle”.

      • Sylvester Krnka also developed metallic cartridge for his rifle, the version used in Russian Krnka it is described here:
        Notice that this is inside-lubricated cartridge predating the .44 S&W Russian cartridge, so the statement that: “.44 S&W Russian is first inside-lubricated cartridge” is hoax. Additionally there is British .450 Boxer Mk. I cartridge which enter service in 1868 and also is inside-lubricated, now I’m wondering that: the British cartridge is copy of Krnka’s or there are independent inventions?

    • I concur Ian, also I found a SALVATOR DORMUS M1896 which was a blowback Austrian military pistol in 8mm Calibre apparently. It’s perhaps of interest, as it externally resembles these Frommer type designs but it doesn’t operate by long recoil – So perhaps the layout was just something they found more natural, because it is more similar to a revolver in regards its grip angle etc.

      • I don’t think the Salvator-Dormus 8mm ever got as far as military trials. According to Ezell, its 8mm cartridges used the standard Austrian military smokeless powder intended for rifles, and the fouling that created tended to bring everything to a halt inside the workings pretty quickly.

        The layout was also used by the 8mm Schwarzlose self-loader of 1892, which was a very strange design operating rather like a Remington rolling-block single-shot rifle action. Its hammer spring was a big V-spring in the grip that also powered its breechblock and Winchester-like cartridge lifter assembly.

        As shown in the illustration on p. 150 of Ezell’s book, the magazine was under the barrel, and held the cartridges in the usual column we expect today, except it was a horizontal “stack” with the cartridge noses down, at right angles to the bore. The lifter rotated each round through 90 degrees to present it to the breech, after first drawing it backward out of the magazine rather like Gabbett-Fairfax “Mars” mechanism. In fact, the whole setup is weirdly similar to the Madsen LMG of the same era, just on a smaller scale.

        To add to the hilarity, the 8mm round it fired was a rimmed, revolver-type round. It doesn’t seem to match up with any other one in Ezell’s book or Barnes’, so it may have been Schwarzlose’s own “proprietary” round.

        I believe the study of these obscure arms is important in addition to being interesting on its own. As W.H.B. Smith once pointed out about the study of single-shot rifle actions, every single one of these actions has resurfaced in the century since they were developed in other guises, notably automatic cannon actions. (Chinn goes into considerable detail on that end in The Machine Gun, especially in Volume 2.)

        Knowing these actions, and their limitations, can save a lot of time, effort and R&D money when one resurfaces, having been “invented” all over again by some fresh-faced expert who thinks he’s stumbled on the Holy Grail of weapon design, and is unaware that he’s just recreating somebody else’s boo-boo of a century or so ago.



    • I’m sure Ian can tel you for certain since he’s handled the pistol. If I have to guess, I’d say it’s a manual bolt lock release. Either that or a takedown latch to allow bolt removal during field stripping.



    • It’s a cartridge release lever.

      If you want to unload the pistol you lock the bolt open by pulling it back while pushing upwards on the slide lock button in the middle of the left hand side plate.

      You then press on this cartridge release lever. This pivots the right hand cartridge feed lip outwards allowing the internal magazine spring to eject all the cartridges.

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