Just Too Powerful: The C96 in 9mm Mauser Export

In an effort to widen its potential marked for the C96 pistol, Mauser offered it in 9x25mm (aka 9mm Mauser Export) as well as the much more common 7.63x25mm cartridge. The 9mm cartridge was made by simply blowing out the bottlenecked 7.63mm case to a straight walled type and loading a 126gr bullet. The two cartridges has the same muzzle velocity (1360fps) and effectively equal ballistic coefficients, so the rear sight graduations were left unchanged (a very clever design feature!). In fact, the only distinctive feature of the 9×25 model aside from its bore and chamber dimensions was the addition of a small divot to the follower to improve feeding with he straight walled case.

Only about 150 examples of 9x25mm C96 appear to have been produced, based on the surviving Mauser order books. The cartridge was also used in the experimental C06/08 Mauser pistol, but it was really too powerful for pistols at the time and found a better home in submachine guns. The Swiss and Austrians both adopted it for SMG use (in the Steyr MP30/34 and the SIG/Kiraly guns).

Mauser Export C96 pistols are found with serial numbers in these ranges:
28,000
78,000
88,000-90,000 (with an “a” suffix)
176,000-180,000

26 Comments

  1. “The Swiss and Austrians both adopted it for SMG use (in the Steyr MP30/34 and the SIG/Kiraly guns).”
    And what about Hungary? It seems that there were more of their 39M (13,300+) and 43M (20,000+) SMGs in service, than Swiss Kiralys and Austrian SMGs in 9×25 combined – more so, as 9×25 was just one of the calibers in both Switzerland and Austria, while for the Hungarian SMGs it was the only chambering. The SIG-Kiraly was manufactured in teen-hundreds, and of the S1-100 developments only several hundred ordered by the Austrian military was in 9×25, the police opting for 9×23, and then bulk of production after the Anschluss was in 9×19

  2. I suspect over 150 were made as there are some examples in the 40XXX and 50XXX range in addition to the ones you mention. Photos of them are in Vol. 2 of the excellent C96: Geschichte & Modelle series by Kersten, Moll and Schmid.

    There’s a very good article on the cartridge in March/April 2002 issue of the International Ammunition Association Journal by John Moss. It details its use in SMGs. In addition to the Hungarian Danuvia SMGs and the Swiss Neuhausens, the Italians made a prototype SMG in this caliber.

    I have some of the ammo, presumably of Austrian manufacture for their MP34s. It’s huge compared to 9mm Para.

    I suppose this leveling up of a pistol cartridge slightly predates or could be considered parallel to downsizing full-size rifle cartridges to make them into intermediate rounds.

  3. I am afraid some wrong ballistic information has crept in. According to DWM and RWS documentation from the 1930s (m/s here converted to fps):
    9 and 7.63 Mauser have quite different muzzle velocities from a 140 mm barrel (1325 fps vs. 1433 fps). The 9 mm has about 13 % more sectional density. Consequently the 9 mm loses 272 fps over a 100 m distance, while the 7.63 loses 341 fps. The 9 mm advantage grows with the distance.

  4. There was something about a Finnish experimental “9mm Lilja” intermediate round, that was tested in modified Suomi SMGs.

    I can’t remember the length of the Lilia round

    I have a sneaky suspicion that the 7mm Sako, which is based on a lengthened and necked down 9mmP case (allowing the presses and some of the other tooling for 9mmP to be used to reduce the costs) shares some history with the 9mm Lilja.

    So, yes, absolutely
    Some experimental intermediate rounds did grow from the pistol side of the diaspora.

    • “(…)Finnish experimental “9mm Lilja” intermediate round, that was tested in modified Suomi SMGs(…)”
      Are you soure about last 2 words? According to http://www.jaegerplatoon.net/ALMOST1.htm
      9 mm Lilja was 9 x 40 mm (Lilja is name of inventor)
      …inspector Erkki Lilja started developing assault-rifle like weapon in year 1943 and built his own prototype in VKT at that time. Just like Lahti he had no official order of any sort for this. Lilja decided to chamber his weapon for intermediate 9-mm cartridge (9 mm x 40) of his own design. This cartridge looks basically like lengthened version of 9 mm x 19 Parabellum/Luger cartridge. Unfortunately this rifle prototype of his remained incomplete until 1970’s…

  5. It is said, 7.62 Tokarev round being powerfull to use in C96 pistols… Since that 9mm much being powerfull than 7.63 Mauser and since this pistol seems similar to 7,63 versions at all but the caliber, what differences could be inside to make in that pistol to use that 9 mm round…

  6. Reminds me of Tim Allen yelling “More power!” on the “Tool Time” segment of the “Home Improvement” show – always with hilarious and, many times, disastrous results. This would be pitsol and ammunition for him

    • Yeah, it appears Americans aren’t the only people obsessed with giving their handguns an absurd amount of PUNCHING POWER!

  7. 1) Did any reeeaallyyy believe a pistol catrridge at a thousand meters, even with a stock – ouside of Chinese warlords. I mean, c’mon….

    2) The Americans and British weren’t the only believers in the efficiency of a big ole pumpkin ball waddling down range. Check out the TKO (Taylor Knock Out) Index, developed by an Great White Hunter in Africa back when men were men…and bottles of gin stood no chance.

    “The “Taylor Knock Out Index” was developed by John Taylor. John Talyor was an extremely experienced African hunter. His formula was based on killing thousands of large game animals with nearly any caliber you can imagine. This formula was designed to give you a relative momentum figure adjusted for bullet diameter. Taylor called it a “power yardstick” for African rifles. The higher the number the better.”

    “John “Pondoro” Taylor, an ivory hunter who over his career shot over 1,000 elephants along with a variety of other African game and who is renowned for writing two books about rifles and cartridges for African hunting, devised the Taylor KO factor to place a mathematical value on the concussive effects a cartridge and bullet would have on an elephant, specifically from a shot to the head when the brain is missed, a “knock out” meaning the elephant was sufficiently stunned by the hit that it would not immediately turn on the hunter or flee.[2][4][5][6][7][8]

    First describing the Taylor KO Factor as “knock out value” or “strike energy” in his African rifles and cartridges, Taylor wrote that muzzle energy is “surely the most misleading thing in the world”, that it is too dependent on muzzle velocity instead of bullet weight and that it is “quite useless if you are trying to compare any two rifles from the point of view of the actual punch inflicted by the bullet” which according to him is more affected by the bullet’s weight. In African rifles and cartridges Taylor compares the effect of a near miss of an elephant’s brain from a frontal head shot with the .416 Rigby and the .470 Nitro Express, two cartridges with similar muzzle energy but different bullet weights. Taylor states that the .416 Rigby will probably not knock the elephant out, but momentarily stun the animal which will recover quickly if not dispatched immediately, while the same shot delivered by the .470 Nitro Express will render the elephant unconscious for up to five minutes. Further, Taylor writes that the .577 Nitro Express will knock an elephant unconscious for around 20 minutes, the .600 Nitro Express around half an hour.[4][6]

    “”The Taylor KO factor conforms to the observations and experiences of Taylor who, along with other very successful elephant hunters such as Deaf Banks, Pete Pearson and Jim Sutherland, preferred large heavy bore rifles for elephant hunting in close country.”

    https://en.wikipedia.org/wiki/Taylor_knock-out_factor

    https://www.n4lcd.com/calc/

    • Then more modern smokeless powders and rifle rounds came around, with great penetration. I think he would have liked the.338 Lapua round after seeing what it does to a human and its penetration. If you penetrate the skull of an elephant with an AP round and it hits the brain, it will go down. It is about modern bullet design and much higher penetration at higher velocities. Poachers use AKM to kill the big beasts, with several FMJ rounds making up the difference of some big piece of lead.

  8. I think the caution is: Don’t use modern 7.62 Tokarev, possibly hotted-up for SMG use, in your 80- to 130-year-old 7.63 Mauser pistol whose locking block you don’t know the history of. Of course if Mauser had sold many more of these 9 x 25s perhaps we would have heard of problems, or perhaps a new gun or an old gun with a new locking block would have been utterly safe — Mauser thought so enough to manufacture and offer this loading.

    I have said before, I still wish 9mm Mauser was around to give .38 Super some metric competition. How does this compare with 7.5 FK Brno?

  9. 9x23mm Winchester is still around, and handily trounces the .38 Super, as well as the 9mm Mauser. With the lighter bullets favored for anti-personnel use, it even matches the .357 Magnum. (But not with heavier hunting bullets).

    It is good to see where it all began.

    • 9 x 23mm Winchester has the problem that it can chamber and fire in .38 Super and 9 x 23mm Bergmann-Bayard (Largo) chambered pistols. Considering its higher pressures, this is likely to cause serious trouble up to and including blowing out the breech.

      The 9mm Winchester Magnum (9 x 29mm) doesn’t have such problems. I believe it is the “longest” 9mm self-loading pistol cartridge ever, being only 4mm shorter than the U.S. .30 Carbine round (7.62 x 33mm).

      As for 7.62 x 25mm Tokarev in any 7.63 x 25mm Mauser chambered arm; DON’T. PERIOD.

      While the two are the same case length, and the “Tok” was in fact derived from the Mauser round, the “Tok’s” shoulder is both further forward and “squarer” than the Mauser’s. Chambering it in a Mauser chamber creates a “crush fit”, which will result in pressure spiking, with a round that already generates higher pressures than the Mauser round. It’s a very good way to blow something up- right in your hand, and in your face.

      Note that 7.63 x 25mm Mauser fired in a 7.62 x 25mm Tokarev chamber will fire-form to 7.62 x 25mm profile, with some minor case-stretch and the possibility of a shorter case neck area.

      As for the 9 x 25mm, I consider it the great missed opportunity of the 1990s. When everybody was concocting “+P” and “+P+” 9 x 19mm loads to try to duplicate .357 Magnum 125-grain ballistics and ME for law enforcement and self-defense use, there sat the forgotten 9 x 25mm, which due to its greater capacity (21.6 grs/H2O vs 11.4 for 9 x 19mm)could generate .357 125-grain ballistics at lower pressures.

      As to actual 9 x 25mm ballistics, Cartridges of the World (6th Ed.) lists the standard DWM factory ammunition as 128 gr. @ 1,362 F/S for 527 FPE, while Military Small Arms of the 20th Century (4th ed.) lists the same bullet weight at 1,350 F/S for 518 FPE. Either one is well up in the .357 range, equaling the performance of 125 gr. JHPs in a 6″ revolver barrel.

      A modern safe-action, double-column magazine “Wondernine” in 9 x 25mm, such as a Glock built on the 20/21-sized frame, loaded with 124-grain JHP bullets, might just end the police/personal defense “stopping power” debate once and for all.

      cheers

      eon

      • Same basic logic gives you the 357 SIG?

        There’s a whole essay to be written on the search for the “ideal” service/duty pistol cartridge in the 350-500ish ft-lbs category. In the US, it’s usually been about cranking up the ballistics a bit from what was in use, trying not to crank up blast/recoil/pressure too much, and then deciding that you had indeed done the latter. Sometimes it works (9 +P, .38 Special), sometimes not (41 Mag), sometimes a bit in the middle and iffy (38 Super, 40 S&W/10mm lite, 357 SIG, 357 Mag).

        • The .357 SiG has pretty much died out because while it generates .357 revolver ballistics, its fat bottlenecked case reduces magazine capacity in medium-frame pistols. What “everybody” wants is maximum capacity plus maximum power, which pretty much means a 9mm with a non-bottlenecked case.

          The 9mm Win. Mag/9 x 29mm falls down, not on power, but because its case is so long it won’t fit in a magazine that will go in a grip that is comfortable for anybody with hands much smaller that, say, Dwayne Hudson’s. The Desert Eagle automatics, in any caliber, have always had the same problem.

          The 9 x 25mm really falls into the “Goldilocks” zone of cartridge design for such a purpose. Not too big (to fit in a graspable magazine/butt), not too small (unable to generate “acceptably” high velocities without “unacceptably” high pressures), and “just about right” in the middle of the range of velocity/energy/bullet weight considered “ideal” by modern theories.

          It’s fairly easy to make, too. Start with virgin civilian .223 Remington cases, cut them to .984″ OAL, then full-length resize, neck-ream, and fire-form. Barnes gave loading data in COTW 6th ed.

          A reasonable factory load would be a 124-grain JHP at 1,350 for about 500 FPE. This would duplicate the 125-grain JHP .357 Magnum used by most police agencies before the shift to automatics, and give an officer (or legally-armed civilian) what would effectively be a 15-shot .357 Magnum.

          A considerably improvement over the alternatives of the last three decades.

          cheers

          eon

          • If we are talking about the striking effect of 9mm FMG bullets on a person, then there is no practical difference between .380 and .357.
            The difference begins to show only when shooting at large animals, when the bullet has a long enough path in the meat.
            Well, or for targets in body armor.

            Regarding the use of 7.62×25 cartridges in the Broum handles, this is permissible, although it is accompanied by some deterioration in accuracy.
            Trouble occurs when a 7.62×25 SMG cartridge appears in the C96.
            In such cases, a breakdown of the locking unit and (or) bulging of the barrel is not uncommon.

      • I don’t disagree with your conclusion, particularly in the context of irreplaceable historical guns (as to my knowledge there are no current-production .30 Mauser guns, and precious few .30 Tok), but I think you’re exaggerating the crush-fit problem.

        Note that the inner corner of the shoulder on the Tok round is actually shorter than the Mauser round, so no interference is possible there or on the neck, and also that the theoretical worst-case interference (CIP max Tok cartridge in CIP min Mauser chamber) at the outer corner is only 0.001″.

        There’s certainly cases where a compression fit is a problem and does spike pressures; if the neck, or the entire shoulder up to its junction with the neck, is a compression fit, the brass will not be able to expand and release the bullet. Instead of jumping to the lands as combustion begins, it will remain still until pressure is sufficient to drive it forward against friction; the additional confinement will of course spike pressure, sometimes dangerously so. These issues are typically not seen with factory ammo, but rather by careless reloaders.

        But when only the outer portion of the shoulder is in contact, as in our case, the neck remains free to expand and the bullet can jump as usual.

        There’s still the general fact that a smaller chamber (no matter whether compression fit or not) will exhibit slightly higher pressure than a looser one, but that’s a small effect while the stuck-bullet issue can be quite large.

  10. Second best SMG round (If you consider the .30 carbine one) of WW2.

    Think it could have massively improved firepower of squads that had SMGs.

    • Maybe. It’s interesting that to my knowledge no-one before the NATO PDW thing really tried to define, from first principles, what an ideal SMG/PDW cartridge would be. The 20s Germans stuck with 9mm because it’s what they had. Everyone else largely ignored the class of weapon before buying whatever the hell the could get or make in actual war. Then the focus shifted onto the universal personal weapon idea. .30” M1 was the closest anyone got, but I’m not convinced how much of the spec was based on science, versus designed on the basis of what was easy to make on the back of a cigarette packet.

      • The major reason for the .30 USC cartridge was to be able to use existing .30 rifle barrel-making machinery. The .32 WSL it was developed from actually had a .318″ bore, so was in fact very close to being a “true” .32 caliber. (It actually used the same bore spec as the bigger, rimmed .32 Winchester Special designed for the Model 1894 lever-action back in 1897.)

        A rimless case was considered better than a semi-rimmed one to avoid feeding problems from a box magazine, something Winchester was aware of with the Model 1907 self-loading carbine.

        Ballistically, it was intended to deliver the same energy at 300 yards (about 400 FPE) as the .45 ACP from the barrel of an SMG did at the muzzle. SMG barrels, being longer, generated slightly higher muzzle velocities and energies than .45 pistols did.

        Also, the .30 USC round was intended to reduce felt recoil in a light, 6 pound, short rifle. Remember, it was intended as a replacement for the .45 pistol with support troops, giving them something easier to actually hit something with than a pistol, while having enough range and power to deal with rifle-armed enemies out to about 300 yards.

        The really amazing thing about the .30 carbine and its ammunition is that Edwin Pugsley & Co. at Winchester got it as nearly right as they did in as short a time as they did. I doubt any design team around today could match that performance.

        cheers

        eon

      • Ironically, 9mm Parabellum became the standard SMG cartridge of NATO not because it was used by the Germans (they lost the war after all) but because it was chosen by Italy and consequently by the British. The British chose it largely because they had captured a very large cache of 9mm ammo from the Italians and designing a weapon around an already abundant cartridge made sense — especially since the British .38/200 revolver round was completely unsuitable for SMG use.

        • True. When the Italian expeditionary force under Graziani was “defeated in detail” in Egypt by the much smaller British force in 1940, the British captured several million rounds of 9 x 19mm ammunition intended for the Beretta Model 1938 SMG. Which meant it was, by modern standards, a “+P” if not “+P+” loading.

          The Sterling Engineering company had already “cloned” the German MP28 to create the Lanchester Machine Carbine for the Royal Navy. The Sten was the British Army’s “answer” to the MP38/40, being cheaper and faster to make than either German design.

          Ironically, after the war, Sterling Co. engineer George Patchett’s design for a new “machine carbine”, the Sterling, replaced the Sten. It was actually a Lanchester redesigned to use stampings rather than machined parts, IOW an MP28 built by Sten techniques.

          cheers

          eon

  11. I am surprised only about 150 were made. Scottish ivory hunter/author W. D. M. “Karamojo” Bell sometimes carried one.

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