The Short-Lived Suomi SMG for Armored Vehicle Mounts

Prior to the Winter War, Finland had just a few armored vehicles; mostly armored cars. These needed some armament, and one idea put forth was to fit an m/31 Suomi to a ball mount inside a vehicle. This required simply designing a specific shroud for the barrel to fit the mount (as well as the pistol grip frame like the Korsu/bunker model), and a spare standard shroud could be carried as well, so the Suomi could be taken out and used if the vehicle needed to be abandoned. Only a few dozen were originally made, and they were all out of service before the end of the Continuation War.

During the wars, Finland was able to capture some Soviet armor, and also a large number of Soviet DT guns. These couple perform the same role as the tank model Suomi, already fit the captured Soviet vehicles, and offered a more powerful cartridge. They completely replaced the small number of tank Suomis in service use.


  1. Looks like a typical firing port SMG from the time. Funny how features turn out quite useful for other purposes like the removeable barrel shroud of the Suomi SMG. What tanks did Finalnd put these into?

    What are the holes on the port collar for?

    • “What tanks did Finalnd put these into?”
      According to
      The total production was probably only about 40 weapons, from which 31 remained in summer of 1940. While the number was small they were intended only for 32 Vickers 6-ton tanks, from which 24 were modified as T-26E. These rare weapons remained included to official Finnish Defence Forces weaponry until 1980’s (long after the T-26E tanks, in which they had been used, were all gone). This may have happened simply because nobody remembered to officially inform them not being needed anymore.
      Where T-26E is Vickers 6 ton up-gunned using Soviet 45 mm gun.

        claims that
        Armament 37 mm Psv.K/36 (L/45) tank gun (50 rounds)
        9 mm Suomi M/31 hull submachine gun (1,444 rounds)

        The original co-axial gun offered was an air-cooled Vickers medium machine gun but this was rejected on the grounds of it being a non-standard calibre (.303 British). It was also thought that adding a co-axial machine-gun would put too much complexity on getting the tanks ready and while it was considered to add the M/09-31 Maxim machine-gun (a domestically produced, improved air-cooled version) it never was produced. This led to the need for a self-defense weapon. The chosen weapon was strangely a submachine gun. It was a specially modified version of the Suomi M/31. The VTT modified the hull by incorporating a firing port which could take the SMG, which had a slim but fixed barrel jacket and a pistol grip but no butt. It had a simple optical sight, took the standard 70-round drum magazine, and performed very well as a self-defense weapon. This also increased the crew complement to four.

        but this does imply they carried 20 fully-loaded drum magazines and 1 loaded with 44 rounds (i.e. half-empty). Was that this case? If yes why that was done?

        • Rejecting the Vickers coaxial because of its caliber seems odd as Vickers (and Maxim) MG are easy to convert to another caliber. Especially as 303 British and 7.62x54R share the same bore diameter.
          The coaxial is not a defensive weapon, it is an offensive weapon complementary to the main gun.

          • “Rejecting the Vickers coaxial because of its caliber seems odd as Vickers (and Maxim) MG are easy to convert to another caliber.”(С)

            Like it or not, You answered yourself. 😉
            There were enough guys in Finland then who would need “MG are easy to convert to another caliber” no less than tankers.

  2. I don’t understand their logic.
    Why did they need to lighten the casing of the barrel?
    If the casing is detached and remains in the tank, why weaken the protection of the barrel against shrapnel and other things?

    • You’re not protecting the bbl w/ a barrel shroud. You’re protecting your hand from being burned when you grab a hot bbl.

      • “…You’re protecting your hand from being burned when you grab a hot bbl…”(С)

        This is, as it were, self-evident.
        The question is, WHOSE hands are you going to protect from the OTHER side of the tank?
        Looking at the German tank machine guns as a model, such a decision seems idiotic…

        The ability to use the device “as is” does not look better.
        It will take more time to unscrew all these screws than to turn into ashes.

  3. Not specific to this variant, but Ian has in the past stated SUOMIs were issued with 2 bbls selected to shoot to the same point of aim, and replacements were readily available for lost and shot out bbls. At one time SUOMI kits were so plentiful and cheap retailers were giving them away as promotional items with another purchase! All those kits and I have never seen one with the second bbl included, and the few retailers that had bbls for sale appeared to be just breaking up the kits into individual parts.

    What happened to all those extra bbls?

    According to one of entrants in NGSW namely MCX-Spear
    (…)MCX-Spear(…)has quite a bit of recoil. Task & Purpose executive editor Jared Keller ended up with several bruises from the rifle digging into his side after he fired 20 rounds during a June 2021 demonstration. Cohen insisted the MCX-Spear has less of a kick than weapons chambered in 7.62 mm.
    If second hold trues then why first? Does MCX-Spear stock or buttplate have some undesired ergonomics feat causing that effect? Is that serious problem or something which was normally exhibited by prototypes of later refined hand-held weapons?

    • This sounds like a joke.
      First, they shout that “soldiers often miss because of the strong recoil.”
      Therefore, everything needs to be lightened and reduced.
      Then, they shout “soldiers still miss often, but now they don’t penetrate armor.”
      Therefore, everything needs to be strengthened and weighted.
      Then they will shout “the soldiers still weakly pierce the armor, but now they have also stopped hitting at all”…
      Therefore, it is necessary to increase and strengthen…

      It’s just some kind of panopticon.
      Circus of freaks…

  5. So what’s up ? Go to FW click for video advance to YouTube click again then nothing. If YouTube does not want the business then that is no priblem. I can waste time in a myriad other diversions. This has been going on for several days.

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