The Lehnar, Argentina’s pioneer subgun

Looks like it’s becoming a series here in TFB to show some South American countries’ earliest and generally unknown submachine gun designs. This time it’s from Argentina, where a designer called Juan Lehnar produced the single prototype of a particularly well-finished 9x19mm selective fire gun in the early 1930s.

Of pretty conventional blowback, open-bolt operation, it featured a cylindrical receiver to house the similar-shaped bolt and return spring. The barrel (length unknown) was involved by a metal sleeve with 12 longitudinal perforations to aid in the heat-dissipation/cooling process, in addition to having most of its length machined in radial fins (remember the M1928A1 Thompson?). The lower receiver housed the firing mechanism, with the fire selector on the left side above the pistol grip with the markings “TIRO” (semi-auto), top; “AUTO” (full-auto), center; and “SEG” (safe), down. Cyclic rate of fire was reported to be in the region of 550 rounds per minute.

Right-side view of the Lehnar SMG in the firing configuration, magazine on the left side, stock extended, forward grip down.

The prototype with the forward grip folded back, stock partially folded down, curved magazine removed. The barrel’s machined cooling fins are discernible through the openings in the external jacket.

There was a wooden forward grip that could be folded rearward, and the skeleton buttstock could be swung forward, thus reducing the gun’s overall length from 700 to 410mm. The 32-round, curved magazine (staggered-column, single position feed) was inserted into the left side, while its housing could be rotated upwards to make the SMG somewhat more compact for transport, at the same time closing the ejection port. The sights (hood-protected front post and 100-200m side-protected notch rear sight) had a radius of 320mm. No weight figures are available.

The gun in the, eh, ‘travelling’ mode. Note that the housing for the curved magazine is rotated upwards, at the same time closing the ejection window.

This closer view shows the magazine housing in the normal position on the left side of gun, while the fire selector markings are perceptible. The pistol grip side panels were made of wood.

This rare prototype was shown to me in Buenos Aires in February 1990 by Pantaleon Kotelchuck, a local gun wizard who worked for the Federal Police at the time and who was also a leading technical advisor to Argentina’s RENAR (Registro Nacional de Armas, National Firearms Register). He passed away in 1993 at the early age of 54.

Argentine gun wizard Pantaleon Kotelchuck posing with the Lehnar subgun for the author in Buenos Aires, February 1990. Note that the weapon is uncocked (bolt forward). Well, just posing…

“Panta” and the Lehnar… ready for business!

Gracias, amigo “Panta”! R.I.P.

Ronaldo Olive

Ronaldo is a long-time (starting in the 1960s) Brazilian writer on aviation, military, LE, and gun subjects, with articles published in local and international (UK, Switzerland, and U.S.) periodicals. His vast experience has made him a frequent guest lecturer and instructor in Brazil’s armed and police forces.


  • Graham2

    A neat looking SMG but was it really made in the early 1930s?

    • Gregory Markle

      Yes, the very, very early 1930s. It was spectacularly bad timing with the world depression going on and few countries looking to purchase any new weapons systems, especially subguns, so subsequently it never got past the prototype phase. By the time it became obvious that tensions were ratcheting up a few years later and militaries began rearming the Lehner had been shelved despite being a fairly advanced design for the time.

  • Major Tom

    And yet it probably would have performed better than the Sten.

  • Dan

    If this really was made in 1933, the history of the Lanchester, Sten, and Sterling SMGs needs to be re-written. Everything from the box containing the FCG under the tube to the rotating (for storage) magwell is too close to be coincidence. Personally, my suspicion is that this is very nice evolution of the Sten, ala AuSten. We’d need to see serious documentation about the 1933 date and some legitimate provenance before we rewrite the Sten history. That history is extraordinarily well documented, and I don’t know of any evidence that the Lanchester and Sten designers crossed the Atlantic.

    I’ve lived in Argentina, it’s a beautiful place. But Argentinians have irrational inferiority complex vis-a-vis Europe that causes them to make wild claims about having invented or owned stuff before Europeans. This sort of thing is what Galtieri et al tapped into when the got the whole country excited about invading the Falkands. Wonderfully ironically for the purposes of this article, a bunch of Sterlings made their way to the South Atlantic and were used in anger against the invaders. Come to think of it, I wouldn’t be surprised if THAT turned out to be the true causal path for how this design ended up in Argentina in 1990….

    • Dan

      And furthermore, we would have to believe that the Germans copied that folding stock with the MP 40 family of SMGs. That magazine looks on my phone to be a Sterling magazine. The stamped welded rear site looks for too modern to be from the 1930s.

      My money is on this thing being a prototype built in the 60s or somewhere thereabouts by some very talented Argentinian arms designer hoping to get business from one of the various military juntas. I would love for Ian from forgotten weapons to look at these photos and give his opinion.

      • PK

        I have a pile of magazines that nearly match that, from 1924. Curved 9x19mm mags were already well established prior to WWII.

        • Dan

          Not the curve as much as the locking area and sheet wrap at the top of the mag

          • PK

            Take a look at the 1922 STA M 9x19mm SMG from France. The idea of mags with a reinforcement band has been around a lot longer than the Sterling.

          • Gregory Markle

            The only thing that I ever thought was innovative with the Sterling magazine was the dual roller follower.

  • Limey

    congrats on taking those prisoners! What was the final outcome?

    • Poyo

      Win-win outcome Limey, we got democracy back and Margaret Thatcher got reelected, it’s a shame that she couldn’t thanks us for that before she died.

      • Limey

        That is a wonderful answer. You win. Good show