MP48: When SIG Cheaps Out

Following the adoption of the WF Bern MP41/44 by the Swiss military, SIG continued to develop its own submachine gun design in hopes of outside commercial and military sales. This is the MP48 pattern, which is a simplified blowback action, but using the same basic receiver geometry as the MK series from the 1930s. The receiver was cast or forged and left with a raw rough texture to reduce costs, and this pattern offered a wire collapsing stock in place of the traditional full wood stock. It also simplified the rear sight to a 4-range rotating set of notches instead of a tangent leaf. The barrel is only 200mm (8”) long, and uses essentially a K31 rifle front sight. The only significant sale of these was to Chile, and it was followed by the SIG 310 model which replaced it wooden furniture with polymer (although the was equally unsuccessful commercially).


  1. This gun was obsolete when designed. By 1948 forged or cast receivers on submachine guns were replaced by stampings; polished, varnished wood by either polymers or metal and adjustable sights by simple fixed sights. Like Jimmy Page, it was a “relic of a different age” (thank you, Paul McCartney)

    • Well, traditionally forged receivers aren’t obsolete on other weapons. They’re just not economical on mass production weapons intended for military usage of this sort. And on the flip side, we can’t be sure that the troops using the MP48 aren’t going to use their guns as bludgeons if fights get too personal. In that role a stamped receiver surrounded by polymer isn’t going to last very long, unless the person on the receiving end of the bludgeoning dies quickly. I could be wrong.

    • “(…)By 1948(…)on submachine guns were replaced(…)polished, varnished wood by either polymers or metal(…)”
      I must protest. Maybe it was in process in replacing, but definitely not replaced
      9 mm SamopalVz. 48a (very same year) sported fixed wooden stock
      M49 (later than 1948) sported fixed wooden stock
      Ingram Model 6 (later than 1948) was offered with wooden furniture of different shapes
      Rexim Favor (later than 1948) among configurations has fixed wooden stock
      Star Z-45 (around 1945, so slightly earlier) sported wooden furniture and collapsible stock
      Beretta Modello 4 (later than 1948) sported fixed wooden stock*
      UZI (later than 1948) in fixed stock variant it is wooden
      CZ 247 (1947 so slightly earlier) sported fixed wooden stock, it also was destined for export
      Lithgow F1 (later than 1948) solid wooden stock

      * one might argue that this should be conflated with MAB 38, if this is case replace using Bernardelli VB

    • “(…)polished, varnished wood by either polymers or metal(…)”
      I must disagree, maybe in 1948 there were in progress of doing so but definitely not finished so. Examples includes, but are not limited to:
      Star Z-45 – Spain, 1945(?)
      CZ 247 – Czechoslovak, around 1947, destined for export
      Bernardelli VB – Italy, 1948 (this is NOT MAB 38 copy)
      Samopal vz. 48a – Czechoslovak, 1948
      Ingram M6 – U.S.A., 1949, there are known 2 variants, both with wooden furniture of different shape, exported to Peru
      M49 – Yugoslavia, 1949 (this is NOT PPSh copy)
      UZI – Israel, fixed stock variant, around 1949
      Lithgow F1 – Australia, 1962, solid wooden stock
      Therefore I conclude that discussed SIG fire-arm was not epigone of wooden-furnitured sub-machine guns.

  2. I can see why Sig failed at sub machine gun manufacturing. It would be like wanting an economy car and asking Rolls Royce to design one.
    I am able to open the video’s again. Thanks for what ever you did to fix that issue.

  3. Investment Cast receiver Body.Similar to German G43 technology.Fine, granular appearance of surface due to solidified porcelain slurry used in forming Mould around Wax model.
    Still used today ( Ruger,
    TRW M14, amongst others.)

  4. What is your opinion of folding magazines?
    Do they feed reliably?
    Do they reduce volume enough to be helpful for second or third line troops (medics, drivers, etc.)?

    • According to
      No manual safety was provided on the weapon, as the folding magazine housing was considered sufficient for this purpose. When magazine was folded forward, to lie horizontally below the barrel, the gun was completely safe and compact. A push on the magazine housing lock button, located on the left side of the gun, released the magazine and permitted it to fall under its own weight to vertical (ready to fire) position, where it was locked by same button-operated catch.
      So in case of this particular model it also serves as (easy to observe) safety. does list weapons with folding magazines, most were produced in limited numbers, exceptions are MAT-49 (so far I know it was deemed reliable) and Danuvia 39.M (here it was mimicry – after it was folded and when observed from afar it looks to be classic short rifle, see upper half of 1st image from top here )

  5. The rate of fire on the MKPS seemed ridiculous, even if the gun could be managed by the shooter. Who needs an anti-aircraft SMG?

    • The idea is to suppress a group in close quarters battle in nothing flat. The MAC-10 in 9 x 19mm fired at 1,100 R/M, emptying its 32-round magazine in one and one-half seconds.

      The idea in each case was that if you fire that many bullets into the area of a typical room in that short a time, you are bound to hit somebody and nobody will have time to duck.

      While not necessarily prudent in open-field combat, for urban operations, especially police-type raids, the application is pretty obvious.

      Just don’t be a hostage. Being a hostage truly sucks; doubly so if the tactical team door-kicker is using something like this.



      • I thought hostage-takers usually tied their hostages to chairs or forced them to lie on the floor so the hostages couldn’t run away. What idiotic terrorist wants the ransom insurance to start sprinting away?

          • Hostage’s fault, anyway. They exercised poor judgment in allowing themselves to be taken hostage in the first place.

            Ask any Russian hostage intervention team. They’ll tell you.

  6. And yet the Aussies and the French show how military submachine guns should be produced with their Owen and MAT49. One wonders if the purists at SIG went apoplectic at seeing the effectiveness of that $30 Owen.

    • They likely went apoplectic at the limited service life of the Owen. Swiss don’t design their weapons to last a single campaign; they design them to last someone from recruit training through to retirement, with as little time spent in depot shops as possible.

      Totally different mentality than what the various WWII armies were looking for, and even a totally different one that most modern military forces, who don’t issue weapons on a career-long basis. I think only the Swiss do that, really…

      • Kirk, The Soviets did a study that, among other things, looked at how long small arms lasted in combat. The answer was less than a month. Which explains the “crude” finish on a lot of Russian equipment. Why waste money, manpower and machine tools on something that is not going to last? (The parts that need to be finely finished are). The decades long lifetime idea is a waste that can’t be afforded by a nation at war.

        • And, likewise, the disposable weapon is a waste of resources for a long-service militia army on the Swiss model. Switzerland likely could not afford to keep their militia-based army operational, if they had had to replace the rifles they issued their troops every couple of years due to the wear-and-tear of training.

          Hell, peacetime training use is enough to blow up a lot of “economy models” with regards to disposable small arms. The M-60 springs to mind; odds are pretty good that the average M-60 gunner during WWIII would have been dead in combat well before his weapon reached its freshness date in terms of rounds fired. And, while that makes a hell of a lot of sense if you’re keeping that gunner and his weapon shrink-wrapped together in some Dutch depot somewhere, ready to expend at need… It makes far less sense if you’re planning on the two of them seeing regular use in training over a period of decades.

          Horses for courses. You have a long-service army that will train a lot? You’d better be buying them long-service weapons. If you see them both as essentially expendable items? Well, that’s your choice; I don’t think it works in the modern era, as we’re seeing in Ukraine. I shudder to think what the Russian Army would look like today, were Ukraine armed-up like Switzerland. Odds are pretty good that their casualty list would be exponentially larger than it already is…

  7. I believe that SIG engineers must have been eating too much chocolate and were unaware of the war that had been raging on their borders.

  8. Y’all railing on the Swiss designers need to recognize something: The STEN and other SMGs of that sort were meant as cheap-and-cheerful stopgaps, disposable weapons for disposable soldiers to use for their predicted 30-second lifespans in combat.

    Swiss weapons were designed to be used for the life of their owner, from initial conscription in their teens all the way through to their retirement from active service in their early fifties or late forties. So, twenty-year lifespan, minimum, on the weapons. That’s why Swiss stuff is so heavy and durable; they’re not designed to last one campaign and be done with; they’re designed to last for the active service life of the guy who’s issued the weapon, and still be usable by the end of it.

    TBH, I’m not even sure that the M16 would meet the minimum requirements for the Swiss; they’re just not durable enough. There are a lot of reasons why the StG57 was as heavily-built as it was, and why the StG90 is as heavy as it is. Durability is probably the key factor… They’re meant to last.

    • “TBH, I’m not even sure that the M16 would meet the minimum requirements for the Swiss; they’re just not durable enough(…)”
      To my understanding M16 is interim solution which will be remove as soon as OICW will be deployed. If it is so there is no much sense in making it very long lasting.

      • Every rifle we’ve issued since the M1 Garand was supposedly an “interim solution” until we came up with the Ultimate Perfect Infantry Individual Weapon.

        Most of the proposals for that UPIIW ended up rather like a real-life version of the Johnny Seven One Man Army.

        The Garand and M1 Carbine were probably the last IWs the Ordnance Board asked to be developed with any clear idea of what they actually wanted. Not to mention the last time they were on the same page as the Infantry School and Continental Army Command.

        The original AR15/M16 doesn’t count; it was a CONARC and then USAF project, that Ordnance opposed. The M16A2 is what the original would have looked like if it had been an Ord project from the start.

        There’s a reason some of us stick to the “old stuff”.



        • Absolutely… I’ve often pointed this out: The US military small arms complex (if you could do so, I’d call it “a Byzantine” or “a confusion”) has a consistency lasting for decades when you look at the manner in which it keeps going for the Ultimate Uber-waffe ™ instead of incremental evolutionary improvements. It also has this minor issue of never listening to the actual practitioners, which is how you wind up with things like the M-60’s sight system and the bipod mounted on the barrel along with an entirely spare gas piston assembly…

          I’d term the majority of the people involved “purblind idiots”, but that would be a base canard and insult to purblind idiots everywhere. I will say, however, that allowing these people to breed is probably bringing the collective IQ down by several points… Eventually, we’re gonna get Eloi out of letting that happen. I personally think that the people running most of our small arms procurement were actually the prototypes for the movie “Idiocracy”, but that’s just the impression I’ve gotten from actually having had to question them on the crapfests they produce and document.

          • CONARC’s 1949 Project Salvo asked a simple question; “Most infantry combat occurs at ranges below 150 meters. What’s the best way to ensure a kill out to that range?”

            After studying combat accounts and even medical reports going back to the American Civil War(!), their answer was; full-automatic fire with a low recoil impulse. Aiming wasn’t necessarily needed. What was needed was a “wall of lead” to cripple or kill anything moving.

            Beginning in June of 1950, events in Korea pretty much proved them correct.

            Ordnance, to put in bluntly, s#!t themselves. They screamed “Marksmanship Tradition!” at the tops of their lungs, and Ord personnel were directly ordered to have absolutely nothing to do with CONARC’s “heretical” program.

            Meanwhile, in Korea, the weapon everybody depended on besides the .30 and .50 Browning MGs was the M2 carbine. Accurate to 200 meters and 950 R/M rate of fire, with a round that hit as hard at 300 meters as a .45ACP out of a Thompson or M3 length barrel did at the muzzle. It proved to be significantly superior to the Shpagin and Sudarev SMGs used by the other side.

            Eugene Stoner at Fairchild noticed this, and designed around it. The result was the AR-15. Ordnance noticed it and rejected the data, and the result was the M14, a “real marksman’s weapon”.

            Sorry. I’ve yet to find an M14, except maybe a really tweaked “accurized” M21, that was as accurate as a standard, out-of-the box Garand. That shorter-stroke gas piston totally buggers the harmonics of the system when it comes to barrel vibration, especially coupled with that skinny, unsupported barrel.

            The Beretta BM59 kind-of/sort-of got around the problem by keeping the heavier Garand-profile barrel and running the forestock almost out to the muzzle as on the parent Garand. This gave the barrel a bit more stiffness, and a bit better consistency. It still wasn’t up to the Garand, but it was somewhat better than the M14.

            Neither one was able to be used effectively in the actual battlespace that existed. Hence the M16 here and the AR70 in Italy.

            Ordnance screwed up the AR15/M16 project any way they could, especially with allowing ball powder to be used instead of the IMR powder that the manufacturer specified. A lot of people think it was deliberate, but I suspect it was just another case of stupidity having the same results by accident as malevolence would have achieved by design.

            Army Ordnance seems to only be worried about beating the Marines at Camp Perry every year. Somebody should remind them that the Leathernecks are, after all, on our side.



          • From the evidence, I think you’d have to conclude that an awful lot of US small arms dementia arises from that whole fantasy tradition of precision marksmanship that we’ve been telling ourselves since 1776. We got a fad started in Europe with the rifle, but that’s about all that BS has really accomplished. The Revolutionary War was won by line infantry armed with French weapons firing French powder, not rugged frontiersmen sniping with Kentucky long rifles from behind trees. Yes, they certainly had impact, but the delusions about those men and guns have had inimical influence down the years until this very day.

            In my humble opinion, Project Salvo went too far in the other direction; “walls of lead” sprayed at random are not really appropriate for most combat actions, especially when you’ve also got to worry about little things like ROE and not killing your random civilians that tend to clutter up the combat zone. Sure, in an environment of unrestricted war? It works; the problem is, there really aren’t too many “unrestricted war” venues, these days. Unless, of course, you’re Russian. Then there are no rules.

            What seems to work best these days, in actual combat? Aimed, semi-auto rifle fire out to about 300m max, backed up by carefully managed MG and 40mm. Full-auto is such a non-issue that I can’t recall ever having been allowed to officially train on it, outside a very limited familiarization with it in Basic Training. It’s one of those things that you just never really question–“Why don’t we train on this…? Oh… ‘Cos they don’t think it’s really important to hit anything when we use it…”. That full-auto position on the rifles, these days? I think it’s more a psychological sop, than anything else.

            Of course, when ya need it, you need it. No idea why they don’t think it’s important to train on it.

            In the final analysis, the individual weapon is increasingly less and less important on the battlefield. Where before it was the basic weapon of the infantry unit, today that weapon is actually the radio. The rifle is merely a self-defense tool that enables the infantryman to survive long enough to call for fire, not the central purpose of the infantryman. Or, so things seem to be trending.

          • “(…)proved to be significantly superior to the Shpagin(…)”
            Wait… how is that if former has capacity 30 and latter 71?

            “(…)Neither one was able to be used effectively in the actual battlespace that existed. Hence the M16 here and the AR70 in Italy.(…)”
            Italians seems to be also fond of M2 Carbine and so Beretta crafted model 57
            it used 7,62 x 33 mm cartridge (same as M2 Carbine) and was also selective-fire but fired slower at 500 rpm.

  9. Dear Daweo,
    Later versions of Shpagin SMG used 30-round box magazines because they were more reliable than 70-round drum magazines.

    • 35-rd. box magazines.

      Whether these were “down loaded” or not, I do not know… Like the 20-rd. box magazines for the M16 and M16A1 that were often loaded to just 18.

  10. Dear eon2,
    Professor Hanlon’s Razor reminds to never attribute to malice what can equally be attributed to stupidity.
    If you think US Army bureaucrats are bumbling idiots, you should look at Canadian Defense Procurement fiascos. The most recent is an announcement by the current Trudeau Liberal gov’t to purchase F-35 fighter jets. Liberal politicians are hoping that voters will forget their election promises to cancel the – too expensive – F-35. Hah! Hah!
    In case you accuse me of being overly harsh in my criticism of Canadian Liberal politicians, you should listen to my rant about what an idiot Conservative Prime Minister John Deifenbaker was when he cancelled the multi-million dollar Avro Arrow fighter jet back during the 1950s.
    Bottom line, every gov’t bureaucrat tries to make his/her department the most efficient, but they rarely have a clue about what neighboring departments are doing.

    • Pournelle’s Iron Law of Bureaucracy states that every bureaucracy eventually transitions to a form where its original purpose is utterly forgotten, and the sole mission of the bureaucracy is to ensure self-perpetuation.

      The worst example of this that I can think of would be the one a friend of mine encountered on an exercise in Turkey. The Turks are ‘effing notorious among NATO forces because if you ever go there on exercise, and neglect to document everything you take in, by serial number… They’ll confiscate it upon their discovery of said item. Paperwork ain’t quite right on those new radios you just installed before boarding the ship going in? Congratulations; you’ve just taken part in an informal military assistance grant to the Turkish military. And, in some forces, you’ll be buying those radios out of your pay…

      In any event, this friend of mine was in charge of doing all the exit paperwork to get their unit out of Turkey. In the process of doing so, he had to drive up to Istanbul, find this literal hole-in-the-wall office, and submit paperwork to get other paperwork stamped so that Turkish Customs wouldn’t seize their entire unit on the way out. In the course of discussing this with the Turkish bureaucrat that worked in that office, he discovered that the office and the requirements he was fulfilling dated back to before the fall of Constantinople to the Turks… Literal Byzantine paperwork.

      Truth of that? I do not know; my friend was a raconteur par excellance. He may have been feeding me a line of BS. But, I do know this for a fact: Everybody I know who’s done an exercise in Turkey just shudders delicately and changes the subject, whenever you bring up the accompanying paperwork.

      One shudders to consider what nightmares of paperwork lurk in the undergrowth in places like China and India, with their long-standing bureaucracies. I understand that a lot of India’s problems with small arms procurement stem from just such issues.

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