TroubleshooterBerlin Fires His Upside-Down Auto-5 FrankenGun!

Long-time TFB friend Axel, AKA TroubleshooterBerlin is the man behind the mysterious upside-down shotgun we blogged about a couple of weeks ago, just before the 2017 SHOT Show. Miles Vining spoke with Axel about his creation (and I mean creation in the “it’s aliiiiive!” sense) at Ventura Munitions during the show, and now Axel has released his own live fire and discussion video regarding the… What do we call it? The ReMG-42/11, maybe? Just watch:

Axel does a good job explaining how he troubleshooted the basic design of the shotgun, including his struggle with spring design, how inverting the shotgun changed the effective size of the ejection port (requiring some weldments to adjust the gun back to functioning), and the general perils of significantly modifying old guns.

There’s something delightfully Metro 2033-esque about Axel’s upside-down gun, as if it were made in underground tunnels by a talented mushroom farmer in the post-demonic apocalypse. In fact, If Axel’s next project isn’t a functioning Bastard rifle I’ll be very disappointed. Of course, one could always compare it to a certain shotgun from another video game franchise, if they wanted to be boring.

Axel told me that his reason for creating this gun was just “because he’d always wanted to”, a feeling I can hardly argue with.

Nathaniel F

Nathaniel is a history enthusiast and firearms hobbyist whose primary interest lies in military small arms technological developments beginning with the smokeless powder era. In addition to contributing to The Firearm Blog, he runs 196,800 Revolutions Per Minute, a blog devoted to modern small arms design and theory. He is also the author of the original web serial Heartblood, which is being updated and edited regularly. He can be reached via email at


  • Arie Heath

    Oh my god, it works. I want one now.

    • M.M.D.C.


    • Suds77

      My thoughts exactly

  • Stephen Paraski

    German Engineering at its finest.

    • BattleshipGrey

      And he doesn’t hate us.

  • M.M.D.C.

    Love the shotgun, Axel. Well done.

    Thanks for the follow up, Nathaniel.

  • Shine on, you crazy diamond.

  • Ben

    Leftys only i guess. Oh well, still cool.

    • gusto

      darn right, about time we got something exclusive

      do you know how many companies that makes rifles introduce cool models/versions and never bother to make a left handed version?

      • Ben

        The majority of which can still be used by leftys. This one, not so much for right handed folks. But it’s a custom job built for him. More power to him.

  • valorius

    Seems like a lot of hassle when you can just go buy a used Beretta 1201FP (rebranded benelli M1) for about $400ish, but it certainly does look cool!

    • iksnilol

      Which isn’t left handed nor top feed.

      • valorius

        I’m left handed the 1201 is perfectly ambidextrous except for the crossbolt safety. (I think someone sells an add on lefty safety though)

  • DetroitMan

    It’s an interesting concept. “That other video game” got me thinking about magazine-over-barrel shotguns and how they would work. I have to think that the traditional magazine-under-barrel works better when trying to feed the gun. Poking shells in from the top just seems more awkward. Since keeping the shotgun topped off is the biggest challenge, I can’t see the magazine-over-barrel design being advantageous.

    It’s still cool and I still want one.

    • iksnilol

      Magazine over barrel is better. Easier to feed shells in (less fumbling under the gun just plop them in from the top). And you get less muzzle flip since the barrel is in line with your shoulder, less bore axis.

      You also get better reliability since gravity helps feed.

      • DetroitMan

        I admit I haven’t tried it myself, but I have seen plenty of practiced shooters who can insert shells with the gun shouldered. If the magazine is above the barrel, you now have to reach over the gun, which requires a complex shoulder rotation.

        I agree that recoil should be easier to control.

        • iksnilol

          Well reloading under requires reaching under the gun. So that feels sorta like a moot point.

          • DetroitMan

            Still similar to loading a detachable magazine rifle.

            In my own experience, I have shot matches with both top loading rifles and detachable magazine rifles. It’s easier to reach under the gun than over.

      • Dougscamo

        100,000 Bren gun users agree…..

      • Darren Hruska

        Pump-action shotguns of this design also use a forward-backward pattern to eject and load a cartridge, which should actually be safer than the traditional backward-forward pattern that we’re all used to.

        • iksnilol

          Never thought about it but you’re right. Can’t shoot off your hand with a short Neostead or other pump forward design.

          Pump forward/mag over barrel is king in regards to SBSs it seems.

  • Tritro29

    If he can build them serially, he’s got a couple hundred customers already.

  • John Bear Ross

    God, I hope he licenses the design and makes a million.
    God, I hope he doesn’t license it to the Freedom Group.

  • E O Local

    I think this is one of the cooler things I’ve seen in a long time. This guy has a way of thinking about gun designs that I wish I had. Keep doing what your doing!

  • CharlesH

    I love the bastard gun, someone make it quick!

  • codfilet

    I admire his skill and mechanical abilities!

  • Graham2

    It’s nice to see the great man himself describe his neat shotgun but it’s a shame the title calls it an auto 5, when we know it’s a Remington Model 11. I know they’re similar but you might as well get it right after all the discussion a few weeks ago.

  • me ohmy

    I remember seeing this guy a few years ago with his blowback unlocked slide version of a beretta 92 auto pistol..and it WORKS!!!

  • Cymond

    So the thing about spotting this in the back of a pickup truck … that was a ruse.
    You knew all along what it was and who made it.

  • Zaro27

    I’m actually working on something like this with my father. I’m trying to convert a left handed 590 into a top-loader. If it works, it’ll be cool. I’m sure someone has done it before, but I’ve never seen one and it’d be a neat father-son project to get my dad into guns post-retirement.