Modern Historical Intermediate Calibers 017: The 7.92x33mm Kurz

The 7.92mm Kurzpatrone 43 (middle right) was developed from the larger 7.92mm German infantry cartridge, represented by the 154gr S Patrone (left) and 198gr sS Patrone (middle left). The 7.92x33 Kurz, as it's more commonly called today, is still used by some forces that retain the WWII-era Sturmgewehrs that fire it. The primary producer of ammunition for these weapons today is Prvi Partizan, which made the cartridge on the far right.

The 7.92mm Kurzpatrone 43 (middle right) was developed from the larger 7.92mm German infantry cartridge, represented by the 154gr S Patrone (left) and 198gr sS Patrone (middle left). The 7.92x33 Kurz, as it's more commonly called today, is still used by some forces that retain the WWII-era Sturmgewehrs that fire it. The primary producer of ammunition for these weapons today is Prvi Partizan, which made the cartridge on the far right.

Many would consider this next round to be the first intermediate cartridge ever, and while that isn’t really true, it is one of the most influential rounds of all time, and perhaps the most influential intermediate round ever developed. I am talking of course about the Nazi-era Kurzpatrone 43 Spitzgeschoß mit Eisenkern, or as it is more commonly called, the 7.92×33 Kurz. This round became the model – in one fashion or another – for numerous intermediate rounds developed all around the globe after World War II, including the promising .280 British, and ubiquitous 7.62x39mm Soviet, as well as several others we’ll discuss in later installments.

At the time, the 7.92×33 round’s biggest rival was the less-powerful US .30 Carbine caliber, to which it is compared in this previous article; therefore, I will not retread that ground. Instead, let’s take a look at how this first generation intermediate compares to our current-generation NATO baseline round, the 5.56mm M855:

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Just by looking at the raw figures, intermediate rounds seem to have gotten a lot better! Yet, not only does the 5.56mm handily outperform the old German 7.92×33 Kurz in ballistics, it’s substantially lighter, too. Compared to 12 grams per shot for M855, the Kurz clocks in at 16.7 grams per shot for wartime steel cased ammunition, or 17.6 grams for current-production Serbian manufactured brass cased.

The point of this comparison isn’t to bash the Kurz, of course, as it’s a far earlier and less optimized round than what is available today. Instead, I wanted to take the opportunity to illustrate just how far this concept has come since 1942!

Note: All ballistic calculations are done with JBM’s Trajectory calculator, using the ballistic coefficient appropriate to the projectile being modeled. Also, keep in mind that there is no single true velocity for a given round; velocity can vary due to a large number of factors, including ambient temperature and chamber dimensions. Instead, I try to use nominal velocity figures that are representative of the capability of the round in question. Finally, in this case I used the standard sight height for an AR-15; the sight height of an actual StG-44 is not substantially different, and this gives a more direct ballistic comparison.

Postscript: Since I’ve decided to expand this series to calibers that – while they may still be ballistically relevant to the wider conversation about intermediate calibers – are no longer actually being produced or tested, I have decided to re-name some of the posts in this series to “Historical Intermediate Calibers”. However, I will retain the same numerical sequence and the word “Modern” struck through. Enjoy!



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 can be reached via email at nathaniel.f@staff.thefirearmblog.com.


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  • RetroG

    Out to about 100 meters, doesn’t seem to be much difference between this and the m855 out of a 20″ barrel, and it actually outperforms it in a 14.5″ barrel out to 200 meters. And the m855 is the result of what, 50 years of development?

    • No. M855, or more properly SS109, was finalized by 1978. I am not sure when exactly development started, but it doesn’t appear to have been any more than a couple of years earlier than that.

      When you say that the Kurzpatrone “outperforms” M855 from a 14.5″ barrel out to 200m, it seems you are referring to the energy graph. Energy is not the whole picture when it comes to lethality. The Kurzpatrone, like M43 and other similar designs, does not exhibit any of the lethality effects we have come to associate with good terminal ballistics, such as rapid-onset tumbling or fragmentation. In contrast, the M855 does (although today there are rounds that perform even better).

      • RetroG

        My apologies, I thought the M855 was more recent design than the SS109. I didn’t realize they were the exact same round. Still had more development time than the Kurzpatrone did, I would wager.

        Yes, I was going by the energy graph, and also the momentum of the round, since I’ve never seen any ballistic gelatin evaluations of the Kurzpatrone (which would be very interesting, at least to me).

        • The Kurzpatrone was in development by Polte over a few years from 1937-1940, depending on how you count it, so it’s not like it was developed instantaneously.

          Regarding momentum, I addressed that subject and explained why momentum is not a relevant metric in this article and video: http://www.thefirearmblog.com/blog/2016/05/01/does-momentum-equal-stopping-power-lets-find-out/

          I think we can be very sure that the Kurzpatrone will perform similarly to other short steel-cored bullets of the same type, such as M43. So therefore, I think we can substitute the performance of the M43 for the Kurzpatrone at similar velocity levels. Fortunately, much has been written about how 7.62×39 M43 performs in both gel and tissue:

          http://www.dtic.mil/dtic/tr/fulltext/u2/a233190.pdf

          http://www.tulprpc.org/attachments/File/wounding_patterns_military_rifles.pdf

          In the second link, Fackler writes what has since become probably the highest-regarded opinion of this cartridge’s lethality among ballisticians:

          “The Soviet AK-47 Kalashnikov fires a full-metal-jacketed, boat-tail bullet that has a copper-plated steel jacket, a large steel core, and some lead between the two. In tissue, this bullet typically travels for about 26cm point-forward before beginning significant yaw. This author observed, on many occasions, the damage pattern shown in Fig 2 while treating battle casualties in Da Nang Vietnam (1968). The typical path through the abdomen caused minimal disruption; holes in organs were similar to those caused by a non-hollow-point handgun bullet. The average uncomplicated thigh wound was about what one would expect from a low-powered handgun: a small, punctate entrance and exit wound with minimal intervening muscle disruption.”

          • ostiariusalpha

            And it wasn’t an isolated innovation either, there were several other competing designs alongside it; four of them besides the Kurzpatrone 43 from Polte Patronenfabrik alone! German ammunition companied had been seriously working on intermediate cartridges since at least four years before Polte was awarded the Heereswaffenamt contract.

          • Kivaari

            Fackler’s comments were what I’ve been trying to relay to people when the subject comes up. It is why some folks that absolutely claim the 7.62×39 is so superior to 5.56mm, even old M193 55 gr FMJBT, miss out of what was really happening in the field. Much of the time the 5.45mm performs like the M43. Thanks for printing Fackler’s view of the wounds cuased by the M43.

          • 5.45mm, by virtue of its smaller caliber, yaws much earlier and therefore disrupts tissue better. From a terminal ballistics perspective, I would consider it almost across the board superior to M43.

            However, it can still produce the same kind of lackluster wounds.

          • Kivaari

            I based my comments upon reports I got from Fackler. The live tissue studies they performed left some pretty minor wounds. Unless the liver or similar organ were hit, the holes tended to be just the shape of the bullet as it was oriented during the tumble. From memory only I believe they tended to do a bi-lobed tumble, which is OK. I remember the intestine wounds were very undramatic. If it didn’t hit a blood vessel causing a bleed out, it was an easy surgical repair using simple sutures. I think the biggest reason was the increase in hits possible because of the new combination of cartridge and rifle. Hits count more than misses.

          • Yeah, I think we’re on the same page on this.

          • Aono

            “5.45mm, by virtue of its smaller caliber, yaws much earlier”

            Would it be more accurate to say “by virtue of its superior form factor?”

          • Aono

            Thanks, I will check that out! At first blush though:

            “It is pointed out that a large value of k may be obtained by the use of bullets having light noses…”

            Wouldn’t this pertain to a VLD relative to, say, a wadcutter? In a VLD the CoG will have a rearward bias due to the relatively long nose. I struggle with the idea that a 5.45 round nose or wadcutter would yaw better than a 5.56 VLD (to illustrate with an extreme example) just due to lower bore diameter alone. Or a .177 round BB.. Shape is paramount or at least relevant, isn’t it?

            I think that it probably is, so form factor seems to me to be the most appropriate fundamental constraint to finding the most efficient cartridge, after cartridge weight and magazine length. All things being equal it will deliver better flatness, wind drift, penetration, and.. yaw? Or no? It’s why the 7N6 is such a great round on paper.

            Incidentally, I’d love to see a 224AR with Berger 90 VLDs in this series for all of the reasons mentioned.

          • Moreso than shape are size and weight distribution that affect yaw.

            Yes, low form factors are good. I’ve done extensive studies on this, and unless you are literally designing a 50 yard brush round, erring on the side of a shorter case and sleeker bullet is pretty much always better.

          • Aono

            All things being equal, a lower i7 would guarantee a longer bullet shape/nose with a more rearward weight bias, since that’s where the case mouth and shank must live in regular cartridges, as well as a relatively flat base ahead of the burning powder column in even caseless or telescoping cartridges. So my assumption is that if bullet materials and construction are equal (whether comparing FMJs or M855A1s), a lower form factor should only increase yaw. The question is whether it predicts yaw tendency such that that tendency scales linearly with the i7, a question you likely already answered for me by showing me equations that hurt my brain.

            The 40gr .204 NTX is another interesting bird in this regard, and might make a neat SCHV example in .204 Ruger (or even better, .20 Practical).

            Thank you for this series and your link! I’ll stop beating this dead horse and let you get on with it. 🙂

          • Don’t forget that increasing the boattail length also helps reduce i7 FF.

          • RetroG

            Fine, the Kurtzpatrone had as much or more development time as the ss109/m885. And the German had as much knowledge of terminal ballistics in the early 1940s as NATO had in the 1970s.

            I mentioned momentum because in physics kinetic energy and momentum are linked by one being the derivative of the other. Momentum does have an impact on terminal ballistics, in that bullets slow by transferring momentum to the medium it is passing through in elastic collisions, or the object it is striking in inelastic collisions.

            While we are on the subject of terminal ballistics, the 5.56 round depends on yawing and fragmentation for a good deal of its wounding and lethality. The critical velocity for this effect appears to be a minimum of 2500fps and optimum of 2800fps, according to Fackler, admittedly for the m193. Out of a 14.5″ barrel, the round drops below this velocity somewhere between 100 and 150 yards, respectively. After that, it just produces a deep, 5.56mm wound. So the Kurtzpatrone would seem to outperform the m885 out of a 14.5″ barrel past 150 yards, in terminal ballistics, since it would leave a deep, 8mm wound.

          • What? The Germans had less knowledge of terminal ballistics in the 1940s than the US alone did in the 1930s, let alone NATO in the 1970s.

            Really, go back and read the discussions I had with commenters about momentum in these two posts, I guarantee you’ll learn something:

            http://www.thefirearmblog.com/blog/2016/04/19/top-4-ballistics-myths-people-believe/

            http://www.thefirearmblog.com/blog/2016/05/01/does-momentum-equal-stopping-power-lets-find-out/

            Yes, momentum is in play when a projectile hits a target, and momentum transference does occur. However, that has nothing to do with the actual lethality and wounding of the projectile. Saying that Round A has more momentum than Round B, therefore Round A is more lethal is nonsense. I demonstrate this over and over again in the comments of those two posts.

            Just because momentum is a factor in kinetic energy doesn’t mean that momentum indicates lethality either. Again, I discuss this at length in the comments sections of those articles.

            I really don’t see the logic that a lot of people, yourself included, use, which goes something like:

            “Round A has a fragmentation range of X yards. Round B is much slower, and doesn’t fragment at all. Therefore, Round B is the superior wounder.”

            What is this nonsense? When rounds like the 7.92×33 or 7.62×39 or whatever penetrate a target and do diddly squad because their bullets are too balanced and too stable and too robust, they just poke holes in the target. But somehow, the 7.92×33 is much more lethal according to this logic, because, um, it wounds like a .32 ACP FMJ, I guess?

            Give me a break!

            Back in reality, the difference in diameter of a projectile makes very, very little difference in its wounding ability. In fact, it makes virtually no difference across the range of projectiles for normal small arms rifle calibers (i.e., .22-.32″). How little of a difference does this make? Such a little difference, that doctors examining the wounds after the fact cannot reliably tell the difference between wounds caused by projectiles of even very different calibers like 9mm and .45!

            I’ll just quote a comment I made on my own blog:

            http://www.tdcaa.com/sites/default/files/page/5%20FRI%20INV%20Molina%20Gunshot%20Wounds.pdf

            “Caliber Determinations
            The caliber of the bullet that caused an entrance in the skin cannot be determined by the diameter
            of the entrance. The size of the hole is due not only to the diameter of the bullet but also to the
            elasticity of the skin and the location of the wound. An entrance wound in an area where the skin
            is tightly stretched will have a diameter different from that of a wound in an area where the skin
            is lax. Similarly, the size of an entrance in bone cannot be used to determine the caliber of the
            bullet that perforated the bone though it can be used to eliminate bullet calibers.”

            http://www.archivesofpathology.org/doi/pdf/10.1043/1543-2165(2006)130%5B1283%3APPOGW%5D2.0.CO%3B2

            “Generally, bullets are identified by their caliber or diameter
            and whether they have a metal covering or jacketing… A simple ruler
            or caliper is a good way to make this determination with
            a bullet recovered at autopsy.”

            http://history.amedd.army.mil/booksdocs/wwii/woundblstcs/

            “The best method of obtaining accurate
            information of this type is to perform an autopsy to locate and identify missiles 4 (fig. 230) and to determine the extent of tissue damage.”

            http://www.e-reading.club/bookreader.php/135302/Gunshot_wounds._Practical_aspects_of_firearms,_ballistics,_and_forensic_techniques.pdf

            “The caliber of the bullet that caused an entrance wound in the skin cannot
            be determined by the diameter of the entrance.”

            This assumption that the wider bullet will do more damage appears to be based on the idea that all bullets create a perfect hole the same size as their diameter, but this is demonstrably untrue. Here’s an image that illustrates this brilliantly:

            http://exclusive.multibriefs.com/images/exclusive/0903bullet2.jpg

            Paper is brittle and weak, but even through it round-nosed projectiles poke ragged, messy holes that do not reflect their actual diameter. Through tissue, which is elastic and resilient, this effect would be even more dramatic. Meanwhile, the wadcutters produce wounds more similar to what everyone assumes all bullets create… But wadcutters are not used in any modern military service projectile (nor should they be)!

          • RetroG

            I was initially just observing something from your charts. Maybe the military shouldn’t have decided on a particular round (m193) out of a particular rifle (20″ M-16) that depends on a minimum velocity to be effective by fragmentation (per Fackler), then proceed to change the load such that it starts at a lower velocity, making the effective range shorter to start with, make it less likely to fragment by design (the ss109) and then shorten the barrel (14.5″) to the point it isn’t really effective out past 100 yards.

            I’m an engineer – we deal with physics all the time. You present me with a mass and a velocity, and I see two things – momentum (I can easily do the calculation in my head) and kinetic energy. KE is so dependent on velocity that the mass is a secondary factor – hence the 1/2 mass component and the velocity squared component. But section density matters a great deal for lethality, as adequate penetration depends on it. Section density is mass divided by cross sectional area (caliber). So mass matters. So does caliber. If the size of the hole doesn’t matter, then we should be fielding 17 caliber rifles. And if kinetic energy is king, then the 220 Swift beats all.

            But it isn’t just KE, as the 5.56×45 and 44 Magnum have roughly the same KE, but different wounding mechanisms and uses.

          • So, this idea that 5.56mm “uses” the fragmentation effect for lethality, while other calibers “use” a different mechanism is very misleading. 5.56mm (both M193 and M855) is capable of devastating fragmentation, if the striking velocity is high enough and if the striking angle is favorable enough. If it does not fragment, it produces a much less dramatic wound, possibly one where the projectile tumbles in the body but does not fragment, or one where the projectile does not start tumbling at all until it leaves the body.

            It seems like this is well understood with regards to 5.56mm, but when it comes to larger, slower rounds like 7.62x39mm M43, people seem to believe that because these rounds lack fragmentation ability, that they therefore must have some other wounding mechanism that 5.56mm knows not. The answer is that they don’t! 7.62x39mm M43 cannot fragment, and so the only way it can produce wounds on the target is through tumbling (which it’s bad at), and via the kinds of poor “through and through” wounds 5.56mm is criticized so much for.

            So it isn’t a choice between fragmentation and some other lethality mechanism, really, it’s a choice between fragmentation and no fragmentation. It’s a choice between maybe fragmenting, or maybe making a wound like a .22 LR, and always making a wound like a .32 ACP.

            The reality is that if you are a US soldier fighting insurgents who shot up heroin before they went into combat, then you will see your buddies be seriously affected when they take a wound, and the enemy may seem almost completely unaffected when you shoot them with your weapon. We have to consider the possibility that this isn’t because the 7.62x39mm M43 is such a superb wounder (it is very well established to be a poor wounder), but because taking OR-grade painkillers before you go into battle makes you more resistant to small arms fire (at least for a little while), and that US troops are not in the practice of doing this (not saying they should).

            I explain an engineering-based theory of small arms wounding in the two posts below:

            http://www.thefirearmblog.com/blog/2016/07/16/ballistics-201-introducing-new-way-thinking-terminal-effectiveness-force-energy-work/

            http://www.thefirearmblog.com/blog/2016/07/17/ballistics-201-introducing-new-way-thinking-terminal-effectiveness-energy-budget/

            Sectional density is very important, but one notes that 5.56mm M855 (0.177) has very similar sectional density to 7.62x39mm M43 (0.183) and 7.92x33mm KzPtr.43SmE (0.173).

            While momentum is obviously a physical force involved in ballistics and the collision of a projectile, it is not directly relevant to lethality. I have addressed this many times:

            http://196800revolutionsperminute.blogspot.com/2014/04/momentum-has-nothing-to-do-with.html

            http://www.thefirearmblog.com/blog/2016/04/19/top-4-ballistics-myths-people-believe/

            http://www.thefirearmblog.com/blog/2016/05/01/does-momentum-equal-stopping-power-lets-find-out/

            Here I address the size of the projectile in relation to the wound it makes (counterintuitively, there is only a very loose relationship here); be sure to read the comments for additional sources:

            http://196800revolutionsperminute.blogspot.com/2016/01/frontal-area-almost-doesnt-matter-for.html

  • Gary Kirk

    Aww, he looks just like his daddy, little taller, and not quite as fat..

  • TechnoTriticale

    Can you caption the image?

    • Weird, it should have been captioned already. I will fix it when I get home.

  • Hoplopfheil

    And the best thing is, it’s just friggin’ adorable!

  • roguetechie

    Nathanael,

    Any chance for 7.92×40 / 41 CETME in this series?

    I find this round just as interesting and potentially relevant as the 5.56 FABRL.

    • I am happy to say that I am in the process of acquiring a 7.92×40 CETME, so yes.

      • Any chance of the 4.6×36 CETME/HK? The Spoon Tip / lightweight cartridge design of the round always fascinated me.

        • I have several rounds of 4.6×36, so I could, but honestly people don’t seem to care about micro-caliber rounds very much.

          • ArjunaKunti

            As the 4.6×36 round fullfills the role of a true intermediate round most effectively it would be very interesting to see in this series.

  • mechamaster

    Maybe compared the 7,92 Kurz statistics with 7,62x39mm and .300 Blackout is more ‘fair’. LoL.

  • guest

    The cartrigde was indeed novel, but already since 1943 the 7,62×39 was being adopted for various carbines, which ended in the 1946-47 USSR assault rifle trials. So the Kurz kartridge was about as “influential” as first jet fighters: influential in the sence that it was a proof of concept, but not much else.

  • Def Tom

    I had a K98k chambered in 8×33 – they were built up on standard wartime K98 8x57IS actions fitted with new stocks and barrels from Lothar Walther by “SM Chemnitzer Sportwaffen und Munitionsfabriken”.got feeding problems when loading more than 3 cartridges because the follower had not been modified for the shorter 8×33 but it relally shot well with hornady 150gn spitzer bullets….though there are not many bullets in .323″ dia made in the 125-150gn weight range.
    They also did some K98´s in 7,62 x 39.