Lahti-Saloranta LS-26: Finland’s Domestic LMG

Finland’s first domestic light machine gun was the LS-26. The prime designer was Aimo Lahti, but because of his relative inexperience and lack of formal credentials, Lieutenant A.E. Saloranta was assigned to assist him. The two did not get along well, and Lahti effectively designed the weapon on his own, with Saloranta helping on the bureaucratic side of things. The gun was a recoil operated on the insistence of the Finnish military, which liked the recoil-operated Maxim and decided it wanted the same system for a light MG. It is an overly complex weapon, but not a fundamentally bad one. It is chambered for 7.62x54R and uses single-feed 20-round magazines that are quite difficult to load. Production (at VKT) ran from 1930 until 1942, with about 5,000 made for the Finnish Army and Civil Guards. An additional 1,200 chambered for 8mm Mauser were shipped to China, where some 30,000 had been ordered – but pressure from Japan shut down the contract.


  1. Hammer fired from a closed bolt? Is there a bolt hold open on an empty magazine? I wonder if the LS-26 was intended to be fired more semi-auto than full-auto.

    The Finns would probably have been better off sticking with the Madsen. At least the magazines would be cheaper to make and easier to load.

    • “Hammer fired from a closed bolt?(…)”
      …Lahti-Saloranta L/S-26 light machine gun is a short-recoil operated, air-cooled, magazine fed weapon which fires from an open bolt.

      “(…)better off sticking with the Madsen(…)”
      Captain Pelo crafted Madsen-que machine gun, namely P-25
      it was submitted for consideration, but reject as dated

      • Clearly, the video illustrated that the LS-26 does not fire from an open bolt. The LS-26 bolt did not lock back after Ian operated the charging handle. The bolt rode forward.

        • states further The system is somewhat unusual as it fires when the barrel and bolt group are already moving forward; this system, borrowed from the Swiss Furrer Lmg 25, significantly reduces the peak recoil blow, because the recoil first has to overcome the significant inertia of the moving barrel / bolt group. This system, also known as “differential recoil”, requires a separate barrel catch which holds the barrel back in the recoiled position. This catch is released only when the bolt is in its forward position after loading the fresh cartridge. The release of the barrel catch permits the entire barrel / barrel extension / bolt group to move forward. During this final movement, a locking lever locks the bolt to the barrel extension, and then the firing pin is released by another lever to discharge the loaded round.
          I hope someone better versed with U.S. taxonomy will deduce if that is mutually exclusive with firing from open bolt xor mutually exclusive wit firing from closed bolt.

  2. Ian thank you for that. Never see this before. Interesting 1920s engineering!
    A little suggestion about the video:
    1) Don’t film in the front of a collectors wall. As nice as it is it definitely distract to see the gun on the table.
    2) Slings. As usual in your videos when the gun has an original old sling you keep it during explanation and disassembly. In my view it always stuck and interfere with the content. Maybe a point to think if to remove the sling is a better option before disassembly?

    • 1) I just press stop and admire the wall and when I am satisfied I continue watching. It is not a TV show or livestream. you can pause at any point of the video. 😉

      2) old leather slings often tear when not properly cared for. Which in old museum pieces they most of the time are. I think Ian does not want to risl damaging the old leather.

    • To be fair working together with Lahti was not easy due to his personality
      According to
      Aimo Lahti oli aikalaistensa mukaan lahjakas, ahkera, sitkeä ja määrätietoinen. Täysin erilaisen työkokemuksen ja vähäisen koulutustaustansa vuoksi hänellä oli huono itsetunto, joka näkyi äkkipikaisuutena, ristiriitaisena käytöksenä ja joskus hankalana persoonallisuutena.
      If my translator do not malfunctioned then that means
      According to his consents, Aimo Lahti was talented, hardworking, resilient and determined. Due to his completely different work experience and low educational background, he had low self-esteem, which was reflected in suddenness, contradictory behavior and sometimes inconvenient personality.

  3. At the 5 minute mark, Ian puts the rather stiff safety on, and uses the pistol grip for leverage. The pistol grip moves noticeably, guessing that wood is now in poor shape after nearly 100 years.

    That’s a LOT of reciprocating mass on one’s shoulder. Pity about the grease. Always entertaining when someone comes from service rifle & greases up their AR-15.

  4. Always has the problem of loading hi-cap magazines with rimmed rounds and potential for feeding issues. I wonder how it would have been with a rimless version of 7.62×54 Russian?

  5. “Lahti did like his Accelerators”

    Both the Lahti-Saloranta and the L35 pistol were replacing short recoil guns which had toggle actions

    It’s notable that when John Moses Browning was designing his heavy machine-gun replacement for the Maxim, he likewise chose to use an accelerator.

    Admittedly, the Browning guns usually have to power a belt feed mechanism, that the Lahtis just don’t have…

    There’s an accelerator hiding in plain sight in the toggle mechanisms of the Maxim and the Luger (and all of those Swiss, Furrer designed toggle locked guns as well)

    As the locked mechanism of a toggle action hits the unlocking (toggle flexing) cams, part of the energy and momentum of the barrel is transferred to the unlocking bolt and toggle.

    Browning had already implicitly shown his understanding of this accelerator, with the gas unlocking system in his “Potato Digger” Machine gun.

    To the extent that the movements of the Bolt and the feeding arm of a Madsen Machinegun are directly powered by the recoiling barrel assembly, it can be argued that the Madsen’s cam tracks also act as “accelerators”

    Lahti was following a strong precedent with his accelerators.

    There’s a definite family resemblance between parts of the Lahti-Saloranta and the style of the L35 Pistol;

    The relief cuts on the square section recoil spring guide

    The cam tracks inside the boxy receiver…

  6. “(…)It is chambered for 7.62x54R and uses single-feed 20-round magazines that are quite difficult to load. (…)”
    Interestingly according to Finnish military used two different types of loading gadgets: small (hand) and large (require tree in order to work)
    There were two versions of loading tools. The larger version had bulk and needed to be attached to tree trunk for using it, but it was also very effective. The smaller version was small enough to fit palm of a hand, but it was not quite as fast to use as the larger version.
    Photo of latter in use is provided.

  7. This all fits with the English language caption on the Finnish Army Museum display of the gun I read in (I think) 1995. The only bit missing is the claim that Finnish soldiers made covers for these guns out of underwear (I guess not their own) in order to keep them firing in the, vowel cold, Winter War. I clearly remember that it was said that this gun was given up by any unit if a Soviet MG was captured.

  8. Like Eric, I was distracted by the Wall o’ Keen Stuff — but in a good way. I especially liked the garland of puukkot to Ian’s left.

    Oh, the gun? If the action spring assembly in the butt stock was too tricky for troops in the field to take apart and put back together, then dammit that’s a design flaw. Issuing it full of cosmoline in the Finnish winter was a staff flaw. Mannerheim should have plucked off somebody’s epaulettes and sent him to the front.

  9. Salorant’s pistol was a hybrid of a Luger and Bergman 2(?) Model.
    But he made a serious mistake when he began to “simplify and improve” the original design of the locking unit.
    As a result, the locking element could not withstand the loads.
    Lahti was smart enough to realize that he was not ready enough to design his own locking assembly.

    Interestingly, Saloranta was so confident of success that he even managed to produce about 20 training versions in 22LR.

  10. What is mind-boggling for me is that they elected to made magazine sticking downwards.
    This is least comfortable solution for loader.
    Many designs against which it was tested have either top sticking magazine (Vickers-Berthier) or side sticking magazine (W+F Lmg 25).
    BAR 1918 (and its’ spawns) have bottom sticking magazines, but it seems that this solution in LMG was fading out in European LMG use in 1920s. Also if Finns earlier used Madsen LMG then it seem to natural to request new LMG to have top-sticking magazine.
    Why Saloranta and Lahti elected to implement downward sticking magazine?

    • Did the Finns mean to use the weapon as a true crew-served weapon, or was it more an uber-Automatic Rifle?

      If you mean to have a crew-served magazine-fed weapon, then the magazine really needs to go on top, like the BREN and its other Czech predecessors. One-man operation, like the BAR? Bottom is actually better, but don’t plan on getting it mounted on a tripod or having someone besides the gunner doing the loading, so rate-of-fire will be lower.

      It’s all trade-offs, all the way down.

  11. All right, time for my rant: Why and hell did designers almost always put a top mounted mage straight up in the middle of the receiver? Okay, the Madsen mag is off to the left, but that was an early and bizarre design. The first model Mendoza is offset to the right, and should have set a trend, but it didn’t. Why couldn’t somebody try mounting his top mag AT A MODEST ANGLE to left or right, keeping things easy for both loader and gunner? Pedersen mounted the mag on his wonky little Device at 45 degrees to the right because he had to keep the Springfield sights clear. Only good thing about his invention.

    • “(…)Pedersen mounted the mag on his wonky little Device at 45 degrees to the right because he had to keep the Springfield sights clear.(…)”
      Pedersen Device was designed to use host weapon in way allowing reverting to original (7,62×63 mm cartridge) thus he could not add holes in host weapon as ability to withstand firing 7,62×63 mm cartridge must be keep.
      For another weapon with diagonally sticking magazine see Garand’s submission for Light Rifle Trial

    • Weapons-carriage always plays a role; try carrying a weapon with a sizable magazine sticking out to the left upper quadrant at 45 degrees or so, and you’ll answer your own question… Same with the “angle it right”, if you’re a lefty, or ever have to fire it from the left shoulder in combat conditions.

      Truth be told, there will always be problems with anything that’s not either fully vertical upwards or downwards; I’m told that the reason the FG42 has only a 20 round magazine when it was meant to be sort of an LMG is that the 30 rounders were too long and heavy, unbalancing the weapon and making it damned hard to carry with one in it.

      In the end, you’ve got to move anything that’s not designed for exclusive use in a fortress mount, somewhere–And, even those you may find yourself having to dismount and go fight with in a corridor. Looking at you, Eben Emael…

      Magazine-fed weapons are always going to have issues with this. Beltfeds typically don’t, which is why we haven’t seen a magazine-fed LMG adopted much, of late. Only one I can think of that made general-issue in the last sixty years is the Chartered Industries Ultimax, and that’s more of a super-duper Automatic Rifle for one-man operation than it is a true LMG…

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