Modern Personal Defense Weapon Calibers 008: The 10x25mm Norma Automatic

Left to right: .38 Special, 9x19mm, .30 Remington, upon which the 10mm was based, 10x25mm Norma Automatic, .45 ACP

Oh yes, it’s that time. The 10mm Automatic, what hasn’t been said about it? Well, a decently sourced article about its history*, maybe, but that’s for another time. Right now, we’re considering the 10mm Auto (or 10mm Norma as it’s more prim and properly called) as a personal defense weapon and submachine gun caliber. The 10mm was designed in 1980 by Swedish company FFV Norma AB with input from Jeff Cooper as the most powerful and capable automatic handgun round of its day, but will that extra power pay off when pushed beyond its design limits into the 50-300m range, at least according to the JBM Ballistics calculator?

Asking this question isn’t so out of left-field. Although the 10mm Auto never had the career in submachine guns that either the .45 ACP or 9mm Parabellum did, it has been suggested for this role a number of times. The FBI, during their very brief adoption of the caliber, commissioned the MP5/10 from Heckler & Koch, who created a model which is to this day one of the rarest production MP5 variants of all time. More recently, KRISS unveiled their 10mm caliber Vector submachine gun, carbine, and pistol, to a decent amount of fanfare. The question of how the 10mm performs in the PDW/SMG role is therefore worthwhile, I think.

Before we hit the charts, I’d like to point out that the numbers I am using for the 10mm are very much on the high end of the spectrum. I did this because I wanted to best represent its full potential as a PDW and SMG caliber, not as a pistol round.

Let’s get into it:

These graphs unfortunately show the 10mm as a little bit of a disappointment in the PDW world. Besides the relatively high energy retention of the 200gr load, there just isn’t much differentiating the 10mm from the 9x19mm or 7.62x25mm. Even the 135gr load – representing the oft-repeated claim that 10mm can give rifle-like performance with lightweight bullets – hardly retains more energy past 150 meters than the 9mm from a submachine gun barrel! In 200gr form, the 10mm does retain substantially more energy and specific energy (energy divided by frontal area, a very rough approximation of raw penetration capability) than do the others thanks to its high muzzle energy, but besides that feels like a fairly normal pistol round. The other thing to note is that even though the 200gr load has the highest retained energy on these charts, it still has less retained energy than the 5.56x30mm MARS covered earlier, and only very slightly more than 5.56x45mm M193 from a 10.5″ barrel. Given the high weight and recoil of this load, this is a little underwhelming.

Weight for the 10mm Auto is intermediate between the 9mm and .45 ACP, at 17 grams per shot for 180gr ammunition. 135gr ammunition, representing the lightest loads in the caliber, can weigh as little as 14 grams, while 200 grain ammunition at the other end of the scale weighs as much as 19.5 grams, very close to .45 ACP.

*If anyone is interested in the true history of the 10mm, check out Dean Speir’s article about its predecessor, the .40 G&A. Sadly, Dean plans to retire his website soon, so enjoy it while you can.

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 is also the author of the original web serial Heartblood, which is being updated and edited regularly. He can be reached via email at


  • ostiariusalpha

    A lot can be forgiven for good energy retention, especially from a well designed SMG. The bullet drop for the full house 10mm is also comparable to or better than the 9mm, so that’s a plus.

    Nate, your velocity graph has a color mistake, I believe. There’s a yellow line curve where there should be the 10x25mm 200gr red line curve, and the 7.62x25mm yellow line is a double of the green in the side bar.

    • Oh yeah, that’s weird. Something screwy with that. I’ll fix it.

      • Tassiebush

        Yeah. 7.62×25 is down twice in first chart showing different results for same load.

  • sadlerbw

    I may have missed this from a previous article, but what is the rationale for choosing 0m-300m as the range to look at for a PDW? I’m not saying it is necessarily a bad choice, I’m just curious how that number was settled on. My gut reaction was, ”Does anyone really plan to use something like an MP5 or PS90 on 300m targets?”, but then I thought about it and didn’t really have an answer to that question.

    • ostiariusalpha

      I suppose if someone is trying to hit your convoy with an RPG from 300 meters, it might be good to know how well your round will work if you and your comrades try to hose him down with your PDWs.

      • nova3930

        Question of mission I think. I’m not sure a PDW is the best choice for convoy protection in terrain where 300m shots are a possibility. Maybe I’m wrong but I always thought PDWs were intended more for rear echelon type duty. In the <100m regime, the 10mm looks like it would work great.

        • CommonSense23

          The PDW concept is pretty much dead in the water except for extremely low visibility ops/VIP protection and when you want to arm cops with something that isn’t a 10inch SBR for political reasons.

          • nova3930

            I don’t disagree with that. That said, if you want something pistol caliber for close in work, you may as well get a pistol bullet with at much thump as possible.

            Course if you’re going that route, why not build a PDW/subgun in 460 Rowland 😀

          • crackedlenses

            I’ve seen ads for a Mac-10-type pistol that was chambered in .460 Rowland.

          • CommonSense23

            But why would you want a pistol caliber to begin with when you can run a rifle round.

          • Chris

            Cause physics…?
            Semiautomatic yeah ! Fullauto …? ?

          • The concept might get a shot in the arm, though, if they decide to adopt something substantially bigger than 5.56mm as the next infantry round, though.

          • CommonSense23

            And then we would have tons of M4s and MK18s lying around to utilize 5.56. I feel the PDW concept is a hangover from when we didn’t realize how effective 5.56 is from a 10inch barrel. And the lack of quality slings, which really changes the ability to carry all day on your back.

        • roguetechie

          No you’re right about what role they’re mostly intended for…

          But, here’s the thing…

          Many of our potential enemies HEAVILY focus on getting forces into our backfield precisely so that they can disrupt our logistics and etc using their well trained units.

          The idea being to generate wildly disproportionate effects on our ability to keep fighting in a relatively “safe way”.

          In other words why attack an armored cav battalion from the front when you can grind them to a halt just as effectively by engaging logistics units with very litle training on employment of their too few weapons?

        • RealitiCzech

          PDWs were for support personnel, but have the problem of being very expensive. Nobody is going to ‘waste’ that much money for support people whose firearms training is mediocre at best.

          • You mean like the Army just did with Modular Handgun System?

          • RealitiCzech

            The price of the Sig is far less than the price of a P90. Despite your support people not having enough time to shoot it worth a damn, it is cheap, so that makes it acceptable.

  • RavishedBoy

    I see 10mm Auto as a round for Desert Eagle (instead of .357 mag), outdoor guns (Glock 40) or modern days’ Coonan.
    As a SMG I think .357 Sig is a better option, I’ve seen it can achieve 2000 – 2100 fps.

    • El Duderino

      How ’bout 9×25 Dillon? I think it would make a terrific PDW round and add a couple hundred FPS to those .357SIG specs.

      • roguetechie

        A wildcat that’s in a similar vein, and absolutely fascinates me is the .38 casull.

        Plus, the whole pursuit of a pdw round and a platform to fire it is an entertaining pursuit mostly because it has so many mutually exclusive and downright incompatible individual puzzle pieces!!

      • RavishedBoy

        I was cosidering common/commercial calibers, not wildcats.

  • Hoplopfheil

    MP5/10 was my weapon of choice in Rogue Spear.

    • Mazryonh

      And then it disappeared from the Tom Clancy games, despite the original author’s frequent mentions of that weapon.

  • Spencerhut

    After many years of avoiding adding yet another caliber to the stable a chance acquisition of ~2k vintage 10mm rounds prompted me to finally get a 10mm. After shooting the vintage 10mm loads for a while in a Grand Power I must say I was not as impressed as I hoped I would be. Even the legendary vintage Norma “Full Power” loads were . . meh. The gun was fine, the power of the ammo left something to be desired compared to plain old .45ACP 230g loads and my hand loaded .40S&W. Perhaps when I start loading 10mm for myself my opinion will shift again.

    • Aono

      The “vintage” full power loads are, out of a 5″ barrel:

      200gr JTC @ 1200 fps 635 Ft/Lbs
      170gr JHP @ 1300 fps 636 Ft/Lbs
      165gr JHP @ 1400 fps 719 Ft/Lbs

      Can you tell us more about the ammo you were using? I’d be really curious.

      • Spencerhut

        I listed the make, weight and even part number on most of them.
        Did you chrono those loads yourself? Looks like wishful marketing guy thinking. The .75″ difference in my test gun is ~75FPS difference, max.

        • Aono

          Sorry, I missed that info in your screenshot. No I have not shot those factory loads, but I have rolled my own with Blue Dot and achieved their velocities within QL and manual pressure specs. Bullet selection does matter a lot. Some HPs are longer than others and eat up case capacity.

        • Aono

          Just to add, I think you might be underestimating the effect of barrel length on this particular cartridge. The factory loads used the now commercially unavailable R-123, which is slower even than Blue Dot, which is as slow as it gets before taking up too much volume in the case. I was loading in a 6″ Tanfo barrel and beating the “vintage” 5″ specs by around 40fps for 180s, while “disadvantaged” by using a faster powder than R-123.

          But when you load for your 4.3″ GP I would recommend going with a faster powder, like Power Pistol, and sticking with lighter bullets, like in the 135-155 class. You ought to be able to get 1500fps out of a Nosler 135 JHP for example. A ~4″ 10mm barrel is kind of like a ~3″ 9mm barrel. There’s going to be a difference, so you have to work with that.

    • El Duderino

      180gr @ 888fps? That’s weaksauce! Factory .40S&W will do better than that.

      • Spencerhut

        Right, lame as h-e double toothpicks.

  • Aono

    I guess I don’t understand the analysis. Do you want a PDW SMG caliber to be a miniature rifle round, i.e. retain velocity? Or do you want it to be a magnum pistol round, i.e. retain energy? This is the trade-off you must accept when you don’t step up to a full-house rifle round.

    Velocity buys you a lot of good benefits. You can kiss the lower envelope of hydrostatic shock, penetrate armor, shoot flat, get good expansion out of a HP. But you sacrifice energy, and energy = penetration, and penetration = terminal effect at range, for example in FBI gel. So you’re trading minimum effective range for rifle-like effects within that effective range. Are you concerned about penetrating body armor? Ok, then you’re done.

    Only the 5.7×28 stands out in terms of velocity and flatness. Only the 10mm stands out in terms of energy. Both, however, are stand-outs. So why is the 10mm a disappointment? What if the standard is achieving minimum 12″ FBI gel penetration at the farthest possible range, and body armor doesn’t come into it? The 10mm has roughly the energy at 300m that the 5.7 has at the muzzle. Does the standard include preventing overpenetration? Then the 10mm has way too much energy. Is that what makes it a disappointment?

    What do you want the ideal PDW SMG to DO?

    • Aono
      • SeeThroughYou

        I would agree regarding most light/fast”PDW” calibers(5.56 is waaay better) but 10mm is a different animal. It has good wound profiles in a conventional pistol while still being able get hits to nearly 300M out of an MP5/10 or similar platform.

        10mm makes sense for support personnel who would be impeded in their jobs by a chest rig or war belt full of rifle mags but are expected to carry at least a pistol. A 10mm “PDW” using the same mags as their sidearm would be an ideal setup requiring a minimally obtrusive LBE kit.

    • For perspective, the 10mm Auto 200gr load retains less energy at 300m than the 5.56x30mm MARS. So the 10mm Auto does better than some other pistol rounds in this regard, but especially given its high weight and recoil, it’s a bit of a disappointment in the big scheme of things among PDW rounds.

      • Aono

        Sure, in a round too large to put in a magazine you can wrap your fingers around, unlike 5.7×28 or 10mm. But just like 5.56×45. So is 5.56×30 just a really bad rifle caliber at the end of the day? And if not, then why isn’t 5.56×45 also a PDW caliber because muh sig brace? Why not 7.62×39? Is there a conceivable situation where end-users will pack 6 30 round magazines for a PDW where ounces start to become pounds? In those situations wouldn’t they just go for a rifle? Should loadout weight even be a consideration or is the smaller size of a PDW round just about optimizing powder charge for barrel length? And then does picking a fast enough powder for 5.56×45 to fully burn in 10″, say, with a 70 TSX on top, do an end run around all this?

        You see what I’m saying. It all goes back to requirements. I know you know this, I’m just hassling.

        • “Sure, in a round too large to put in a magazine you can wrap your fingers around, unlike 5.7×28 or 10mm.”

          Unlike 5.7x28mm, the 10mm has far too much recoil for a machine pistol. And as noted in the post proper, this discussion centers PDWs and SMGs, not semiautomatic pistols.

          “But just like 5.56×45. So is 5.56×30 just a really bad rifle caliber at the end of the day?”

          It’s a low powered rifle caliber, and even it kicks 10mm’s ass in pretty much every measurable way.

          “And if not, then why isn’t 5.56×45 also a PDW caliber because muh sig brace? Why not 7.62×39?”

          Here’s an article I did a long time back showing a lineup of PDW rounds. You will note that 5.56×45 and 7.62×39 (and .300 Blackout and 5.45×39 and 6.8mm SPC) are among them:

          As to why there haven’t been MPDWC articles on the 7.62×39 and 5.56×45, that’s because I did MIC articles on both calibers:

          “Is there a conceivable situation where end-users will pack 6 30 round magazines for a PDW where ounces start to become pounds? In those situations wouldn’t they just go for a rifle?”

          The recoil is more the issue for 10mm. But yeah, I can think of a reason why “ounces become pounds” for these calibers: If the 5.56mm is replaced by a larger round, a smaller round will likely be needed to not only fill the PDW role, but also the subcarbine and SMG roles. So you would in those situations absolutely have people packing on ammo, and in for that a “PDW” round that is heavier than your standard rifle round would be a drag.

          “Should loadout weight even be a consideration or is the smaller size of a PDW round just about optimizing powder charge for barrel length?”

          Weight should always be considered.

          “And then does picking a fast enough powder for 5.56×45 to fully burn in 10″, say, with a 70 TSX on top, do an end run around all this?”

          In most situations, yes, a 5.56mm rifle loaded with, say, Mk. 318 will be a better choice than virtually all of these PDW calibers. But there are other ideas we can explore, which is the point of this series and the reason I bothered to do an article on 10mm.

          • Aono

            Ok, so if I am reading your tea leaves correctly, then your notional requirement is for the lightest possible cartridge that sits between 9mm and legacy 5.56 (which together with .308 is now 6.5CT because NATO logistics, because CT is the only way 5.56 ever goes away), with an effective range of 300m, out of a 10 inch barrel.

            Stipulate that the reasonable “effective” threshold at 300m is 500 joules, same as 124gr 9mm at the muzzle. Stipulate projectile has same form factor as M855A1 to account for similar bullet construction.

            IMO what you’re going to end up with is a .204 caliber 55gr projectile with a G7 of .152 doing 2600fps from a 10″ barrel. I think that is eminently doable at 5.56 pressure, and would result in a slightly shorter COAL than the notional 5.56CT, putting pistol grip mags and holsters back in play and 9mm in peril. 55gr M193 is already 100fps faster out of a Mk18, so that helps to account for swept bore volume. It will still be doing 2000fps at 200m, and between that and the M855A1 style projectile it will likely be an LIII penetrator too.

            If they want to combine replace 308 with 6.5, then they’re going to need to go smaller than 5.56 for all of the same reasons for its replacement. So that’s my modest proposal. Am I crazy?

          • J

            No there is one single option to replace both with one, having 66,66% the weight of 5.56×45 and ~53% the weight of 6.5 CT but 351ft lbs at 1200meter like 6.5CT 123grain 3000fps assuming 0.264G7 BC, but specific Patents are required for such performance, without them, there is no way.

            CT6.5 is, to say it nicely verry suboptimal, they said its 123grain 3000fps, but the carbine barrel is too short for that, the heat flux and blast will be way to high. And Recoil Impulse is 168.7% higher and the Recoil Energy 286.6% higher than 5.56×45. The Magazin capacity is only 20rounds. Sicnificantly reducing hit propability under stress and increase time needed for follow up shots when the first was a miss, opponents arent paper targets on a range but mostly only present a ~6″ silhouette.

          • J

            *Oh you seem to rather speak about Pistol/SMG not mid-range Rifles/Carbines.

          • I don’t have a requirements list. The main purpose of the Modern Calibers series is to lay a groundwork for my readers so that future discussions of weapon ballistics can be better informed and more fact-based.

          • It would be an interesting article to refine what a PDW should offer in terms of performance, and then re-evaluate the various rounds through that lens.

            If the PDW is designed to offer more then a 9mm pistol, but less then an assault rifle, then the performance of the cartridge should be in the middle of the two; expecting a PDW to offer good performance at 300 yards seems to ask too much.

            If a 9mm pistol has a practical effective range of 50 meters, and the average assault rifle/ammo combo has a practical effective range of 300 meters, then 150 meters practical effective range seems like a reasonable standard for a PDW.

            Practical effective range being a mix of projectile performance (either expanding, fragmenting, or penetrating a IIIA helmet/vest depending on goal) and having a high first round hit probability on a prone rifleman target.

            With those standards, it’s finding the right cartridge that offers the best blend of 0-150 unprotected and armored terminal performance, controllability, cartridge weight, and the ability to fit into a grip inserted magazine.

    • GnarlyNardHair

      Frankly while I find these articles mildly interesting, it’s always seemed to me that Nathaniel F. is biased against certain cartridges and will change his reasoning/justification at will to support his biases. Sorta like how he’ll make any kind of tortured logic necessary to bash 6.5 Grendel but insists that 7.62×39 with mythical bullets that don’t exist is the best ammo ever. It’s pretty strange.

      • Aono

        Well, I find these articles highly interesting and find that NF enjoys being provocative particularly in cases where he can back up his opinions with facts. That’s why prodding him in turn is so much fun, because then he tends to excrete more facts for all to enjoy. For what it’s worth, I also don’t actually recall him bashing the Grendel, but I do recall him bashing the 6.8. Which is, well, a turd. Because facts.

        • To some people, saying the US Army won’t and shouldn’t adopt the Grendel is “bashing” it.

          • Aono

            I backed away slowly from this thread after BRM’s comment because I didn’t want to get between you and someone who could possibly be your psychotic ex girlfriend.

            But I’m glad I did because the aftermath cracked me up. Have you watched Chris Bartocci’s video on the 6.8? He makes it sound like Steve Holland basically sweet talked Remington and others into going in deep on this caliber when there was never any actual demand for it in the Army, and especially not after Mk262. Personally my favorite part about the 6.8 saga is the STANAG to Six8 trajectory. Just, WAT..

      • iksnilol

        9.7 gram bullets in 7.62×39 is a far cry from mythical-

      • 170gr soft points?

    • valorius

      10mm has vastly more recoil than 5.7mm. Probably too much for a PDW. I like 10mm, but they’re not comparable in any way really.

  • Echo5Charlie

    I love charts that mix and match units of measure! So informative.

    • Hard to avoid in this business. I realize everyone may not be happy with the compromises I make in this regard, but I tried to use the units that most people would be familiar with (e.g., ft/s, grains) or which military requirements are centered around (meters).

      Oh, and I used Joules because seriously, ft-lbs are stupid.

  • Keiichi

    There are some solid copper 10mm bullets in the 115 – 125 grain range, though cartridges loaded with them aren’t usually designed to push velocity limits…

  • Keiichi

    If the purpose of the rifle is fun / range toy, 10mm is a great choice. A bit spendy compared to 9mm, but the extra drama of even middling 10mm loads is far more entertaining, imo.

  • 4949shooter

    The 10mm was never intended to give rifle-like performance, even in a SMG.
    It is what it is, a powerful service type caliber. Nothing more and nothing less.

  • Alexandru Ianu

    It’s funny how some people still claim that the 10mm exceeds .357 (or even .44) in energy – that’s only the case for very stubby barrels where it burns more efficiently..

    Still, it’s a good thing it’s not too powerful of a round, since it’s still supposed to be pistol ammunition, not intermediate.

  • Herp

    Why do we keep having this conversation? If you want a vehicle that’s bigger, heavier, and more powerful, you need more horsepower.

    A rifle is the answer if you need a weapon that’s more formidable than a pistol. The bullet either fits in a pistol grip magwell or it doesn’t. If it does, and a pistol will do, use a pistol. Don’t just throw a fun switch and a shoulder stock on a pistol and say it’s bridging some gap.

    It’s like throwing a truck chassis on an economy car power train in case you need to drag race.

    • iksnilol

      But bigger, heavier and more powerful is for dragracers who are like the lowest form of racers.

      That lot legitimately disgusts me. “OOh, look at me, I can go in a straight line for 5 seconds”.

  • Recoil

    Nathaniel you REALLY should implement an Recoil chart…!

  • valorius

    I like 10mm, but i wouldn’t consider it a PDW round.

  • Brian Mead

    >10mm from an SMG performs like 9×19 @ 150M
    >Therefore it’s not worthwhile
    >Forgot to mention SMG range has always been <50M

    Granted, 10mm auto, even in its hottest loads, is still a solid 30% weaker than rounds like 545/556, riflelike performance my foot! However, at short range, its power is overwhelming for a handgun round, so I'd call it a good SMG pick if somewhat unorthodox.

    Oh, Nat, you never change.

    • >mad that I could possibly disparage the 10mm as used in a role it was never designed for
      >mispeaks and accidentally suggests that 9×19 performs at 150m like 10mm performs at the muzzle
      >blatantly disregards WWII and the entire history of military use of submachines and claims that they’ve never been designed for use over 50m

      • Brian Mead

        I’m not a 10mmNorma fan. I just find you have a long history of setting crazy parameters to support whatever conclusion you want. Well memed. Unfortunately, Operation Cwal and There is
        No Cow Level.

      • Mazryonh

        Could the old WWII SMGs hit out past 200 meters without a lot of sight adjustment? It would be much easier with the 10mm. I also remember reading from Anthony Williams’ work that larger-diameter rounds suppress better at a distance as well.

        If we’re going to talk about Starcraft, the U-238 Shell range-extending upgrade was considered nigh-essential for basic Terran Marines in the first game. But in real life better effective range hasn’t always been a deciding factor for SMGs.

  • I have never deleted a comment on TFB ever. Do you know how I know?

    Because I can’t.

    “Threads around the web disproving me”. You mean one thread on 6.8 Forums where they got their hackles up and did nothing to address my actual data which I got from their administrator!

    • iksnilol

      You should get a medal for that 6.8 “incident”. So many jimmies rustled… Heck, still rustling them.

      • Oh I still get loads of emails. I think that still is the longest comment string in my TFB career.

        • iksnilol

          Do you ever feel that you peaked then and there?

          • Nope.

          • iksnilol

            Mother of God… you’re gonna do it again? You’re gonna unleash a new wave of butthurt across the gunweb ?

            The day of reckoning truly shall be beautiful

  • No one

    Since when have 6.8 fanboys disproved anything said about that garbage bin of a cartridge exactly?

    They usually just shout *WELL, 6.8MM SPC IS THE BESTEST ROUND EVER BECAUSE…..ERM….BIG BULLET!” and then flee in the fact of actual facts declaring victory.

    Or they’re just outright liars, deceivers and frauds like their cult leader Gary Roberts. (and, unlike Nathaniel F being some super 5.56mm fanboy, there’s a load of evidence for Gary Roberts being a lying, manipulative hack.)

  • CavScout

    Good going not testing the 180gr, the optimal bullet weight for that caliber. Just like 165gr is better for energy in .40s&w than 155gr or 180gr…

    And I don’t even like 10mm…