Experimental Bullpup Over/Under Shotgun with a Secret

This is a prototype or one-off over/under sporting shotgun, made in a bullpup configuration. It is basically two long slabs of wood clamshell around a pair of barrels, with the action at the very end in the stock. The breech rotates up to open, activated by a lever on the surface of the buttplate. That’s certainly strange enough to be interesting, but there’s more…the barrels are actually gently curved inside the furniture. And they have to be, in order to line up with both the stock and the sight rib. Crazy!

Sold for $2,300 at the December 2019 RIA Premier auction.



  1. Can only be cleaned with a pull-through?

    If the top rib is aluminum this must be a 20th-Century construction?

    Nice grain and finish on the stock wood.

  2. I love it. It answers a problem no-one knew even existed!

    Obviously, this was made by a talented tinkerer. The barrel opening latch in the butt seems to be the fore end latch from a side by side shotgun. The lines of the pistol grip and rear hump remind me of a Browning Auto 5.

    I agree the curved barrels should not affect accuracy. All we need is someone brave enough to fire it.

    • Lets see… mechanically untypical, aesthetically somewhat antique looking. How to describe it shorty? steam-punk I guess.

  3. Even if the shot could be persuaded by the straight-away to the muzzle, what would felt recoil be like when projectiles had to make a turn halfway along?

  4. Interestingly, the very same gun (look at the marks in the furniture along the barrels) has been auctioned by Rock Island once before in 2014 (https://www.icollector.com/Interesting-and-Unique-Belgian-Bullpup-Style-Prototype-Over-Under-10-Gauge-Shotgun_i19367597). But back then it has been describe as being of Belgian origin. It would be really interesting to take the gun out of its stock and see what proof and producer marks may appear
    I agree with Ian that someone had an idea and tinkered with existing gun parts. But I cannot help myself wondering whether this idea has gotten around somehow in Europe. There was a company in Germany called Steinkamp Waffenbau GmbH (now being renamed Steinkamp GmbH & Co. KG), that sold a gun (Steinkamp SW1) based on a design by Anatol Görzen (https://patents.google.com/patent/US7493718B2/en) quite similar in design to our mystery shotgun in 2008 (https://www.thefirearmblog.com/blog/2009/11/21/steinkamp-sw1-the-bullpup-double-rifle-shotgun/ https://www.youtube.com/watch?v=WZOPGQpNvh4). The Pfeifer SR2/SR3 series of rifles from Pfeifer Waffenbau in Austria (https://www.pfeifer-waffen.at/home.html https://www.youtube.com/watch?v=KqozkVb1JmU) although being single shot, also works with a similar system. Well, both guns lack curved barrels, but this is more difficult to work in a rifle than in a shotgun, as we all know.
    Like I said, I am just wondering whether these two companies knew of this shotgun, or if they came up with the idea themselves (a case of “convergent evolution”, so to speak).

  5. My best SWAG is that it was custom made for a physically impaired shooter. Most likely someone confined to a wheelchair. It would allow them to shoot skeet or trap without the problem of the forward weight of a standard-layout O/U gun. Balancing at the pistol grip as it does, it could conceivably be fired one-handed from the sitting position.

    The barrels were certainly from a “commercial” gun, but everything else about it appears to have been hand-built. Note that it took considerable skill in metalworking to curve those barrels without weakening them.

    This gun is almost certainly one of a kind, and if the barrels could be checked for manufacturer’s marks and serial numbers, there’s
    a good chance it could lead to (a) who built it, (B) who it was built for, and (C) why.

    Again, just a SWAG.



    • You might be right with serving person with disability. Hard to imagine any other reason. Forming twin barrel in this manner it is likely not easy undertaking. For one thing, barrels may be brazed together and by bending them they may separate. Also, their crystallic structure might be affected/weakened.

    • Chern, getting a slug stuck wouldn’t be too much of a problem. Having a slug exit somewhere other than the muzzle could be exciting.

      That is a fascinating gun layout. You could make a 26″ legal stocked shotgun w/ 24″ bbls.

      You could make 24″ bbls in a spiral that was only 12″ long…

    • I believe a sabot slug would work. Remington 12 gauge sabot slugs are .58 caliber, and that wouldn’t bind in the barrel. Whether or not the barrels are thick enough to take the pressure, I can’t say.

  6. The covers and leaver for the breach remind me something such as a 960 Singer Sewing Machine.

    So if there’s any connection (pure speculation) it could be 1900-ish American made.

    I’m sure the fasteners could be dated and regioned, which could accurately place it to an era at least.

  7. Staggering bizarre. If any further information ever comes to light. Could you ‘revisit’ it / do another updated piece.

  8. A curved barrel like that might have been intended to put backspin on spherical shot.
    Like a Tippmann flatline paintball marker barrel — projectile rolls along the top surface of the barrel.

    Same principle as a fastball, backspin grabs some of the airflow and directs it downwards, which enables a flatter trajectory.

    Would be interesting to see if it works.

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