Bullpup 2016: Vadum Electronic eBP-22 Bullpup

We covered the Vadum electronic .22 LR several months ago with a comprehensive review on TFB (very solid review by Tom R). Since then, the Vadum team has been working away at the design, and had it not only on display at Bullpup 2016 but also available for live fire down at the demo ranges.

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So what makes the Vadum electronic? The only electronic part of this firearm is the trigger linkage to the hammer. The trigger is attached to a bar that presses down on an electronic apparatus which then allows the hammer to fall per single trigger press. This apparatus is charged via a 9 Volt battery which is slid in through the right side of the frame. An Off/On switch can turn the apparatus off and on, and is mounted on the left side of the frame, just ahead of the trigger. If the battery runs out, there is no secondary manual hammer system should the electronic fail. One of the biggest drawbacks of bullpups from a civilian perspective are the long trigger linkages that cause excessive trigger pull. With electronics, the eBP-22 is able to get the pull down to mere ounces instead of pounds.

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The rifle has much in common with the Ruger 10/22 platform, sharing the barrel and magazines. The bolt is a factory Ruger bolt, modified to include a rear radius (smoother charging, better cycling with standard velocity and subsonic), as well as a firing pin anti-rise crosspin. It will accept standard unmodified Ruger bolts as well.. The frame is very nicely designed, being compact, with a telescoping stock that slides right into the overall frame. The company has incorporated common features such as picatinny rails, an AR style pistol grip, and a threaded barrel for suppressors.

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Infantry Marine, based in the Midwest. Specifically interested in small arms history, development, and usage within the MENA region and Central Asia. To that end, I run Silah Report, a website dedicated to analyzing small arms history and news out of MENA and Central Asia.

Please feel free to get in touch with me about something I can add to a post, an error I’ve made, or if you just want to talk guns. I can be reached at miles@tfb.tv


  • gunsandrockets

    Okay, that’s a nifty solution to one bullpup problem.

  • Arie Heath

    That’s certainly inventive. I kind of want one now.

  • randomswede

    If they get this past the ATF I’ll be very surprised; but money is going into it so someone must know something I don’t.

    • Giolli Joker

      The link is in the article so I’m being lazy, but I kinda remember that the issue was addressed in the original review… something related to ATF approval given some features of the trigger group making impossible to reprogram it to shoot full auto.

      • randomswede

        I’ll have to delve deeper.

        • Emfourty Gasmask

          This is such a basic electronic circuit that anything they do could easily be overcome with a little bit of electrical know-how.

          Of course, it goes without saying, it would be a very illegal modification.. Much like many illegal, easy to do modifications exist for current semi-auto weapons. ( And, incidentally, some questionably legal. )

  • therealgreenplease

    For a fun gun I have no problems with an electronic trigger. If you wanted to make it more reliable you could have the battery recharge from a TEC wedged between the barrel and some aluminum rail.

    • Giolli Joker

      Would the temperature difference generated by 22LR be enough?

      • therealgreenplease

        Now that I think of it, probably not. Perhaps if the barrel extension/chamber was made of TEC material but, mechanically, TECs tend to be weak. Solar panel somewhere on the weapon would likely be a better option. I’d imagine each trigger pull uses very very very little energy.

        • Giolli Joker

          I guess it would be easier and more reliable to generate power by harnessing some kinetic energy from the bolt movement, being the gun a simple blowback.

          • therealgreenplease

            That’s a good point too. You could have a recess in the bolt carrier and then embed magnets still holding it ~1mm from the inside of the receiver. Just put copper traces on top of the anodized AL (I can’t think of any problems immediately but there may be some…) and the motion of the bolt will induce a current. This setup would actually slow the BCG too, kind of like a spring.

  • Jack

    Looks like a great way to get a sore thumb from loading mags!!

  • Giolli Joker

    They could mount the grip on a rail to allow its position to be adjusted on user’s preference.

  • Sasquatch

    Just like my electronic paintball gun.

  • Disarmed in CA

    EPROM for staccato trigger pulses is just a gun and computer nerd away, I would think.

    • Or any of a hundred existing paintball control boards.

  • Derrick

    Makes me wonder if you could somehow make electronic firearms more reliabe through some sort of secondary system that charges a backup battery of some sort thats charged through the energy of the rounds being fired incase the main one fails or dies

    • gusto

      or like in those clocks that wind up by the swing of your arm?

      or like a solarpanel like a small calculator?

      or even a small crank like a windup radio?

      it should have atleast one if not more of a backup system

      • noob

        well an internal combustion engine uses electricity for the ignition, but your car doesn’t need you to throw away the battery when it goes flat.

        instead the battery is continually recharged when the motor is running – you could have some sort of alternator in the gun using the recoil energy or some tapped gas to charge the onboard gun battery as well.

        • Vizzini

          Yes, that’s an excellent idea. There’s a tremendous amount of recoil energy to be harnessed.

          Of course, each modification you make further complicates the mechanism as a whole, so that many failures will not be fixable in the field or with simple machined parts.

    • aka_mythos

      I keep thinking of those flashlights that recharge by shaking them. An iron or steel core passing through a copper coil that charges a small battery or capacitor. Imagine that in the rear buffer tube portion of an AR looking like one of those drop in pneumatic buffer alternatives.

      That magic balancing point is if you can get the electronics to function off the power of a single stroke of that charger, then you’re powering the electronics from a generator powered by the recoil and cycle of the weapon… and then the battery is a redundancy.

      • Hoplopfheil

        What about a regenerative braking style system?

        Electric motor delayed blowback… Make the bolt work against the motor to charge a capacitor or KERS (flywheel?) System, then tap off the power to trigger the next shot!

        • BRamos

          The bolt is already made of steel so add copper coils to the buffer tube or the back of the reciever and that might work. Or was that what you were getting at?

          Some testing might be in order.

        • aka_mythos

          What I’m talking about I think is simpler and is more like the electromagnetic recuperative active suspension systems which work better with impulses as opposed to torque input. To induce a spin on a fly wheel would require a more complicated mechanism, either with gears or linkage like a toggle lock that might be reminiscent of the a Kriss Vectors or a Luger.

          • Hoplopfheil

            Yeah I’m thinking batteries are more simple. But I like the idea of a totally mechanical KERS system.

          • aka_mythos

            What I was saying …simpler than a flywheel.

            While a firearm may become more involved in its design its about the advantages it brings to the table. The evolution from a gun just being a tube with a fuse to a matchlock to a flintlock… etc has add greater complexity but brought reliability and improved ergonomics. While complexity introduces the opportunities for failure technology is about creating the tools to ensure those failures are practically eliminated.

      • Anonymous

        There is plenty of energy in a .22LR blowback to harvest. However, adding a coil and magnet adds more cost, moving parts, etc., and it places electronic components near the dirty part of the gun, where they might be exposed to cleaning solvents, etc. A 9V battery is a pretty simple solution, lightweight, available in any store for decades, available in all chemistries (alkaline, NiCd, lithium primary, LiPo). This gun doesn’t just “stop” working – as the battery dies, the refresh rate will slow – basically, if you notice that you can’t double-tap with immediate refresh, you have several thousand shots left at a slower rate of fire. It will actually run from a dead (<7V discharged) 9V battery, just not as fast.

        • aka_mythos

          The issues of extra parts and environmental wear and tear is why I liken it to those pneumatic buffer and spring replacements. Those are enclosed and located relatively far away from the combustion of the weapon and don’t generally suffer from the issues related to fouling. They have only as many more parts as the sort of recharger I’m talking about. Ultimately the recharger would replace fluid resistance for electro-magnetic resistance, which generally sees even less wear then a pneumatic system.

          The goal of what I’m talking about is where the power generated by the recharger would be roughly equal to what’s consumed in the electronic release of the hammer. In that way a battery is mostly a redundancy and a back up largely to compensate for any inconsistencies in the power generation.

      • imbecile

        Was thinking about this kind of thing myself. Just a coil with a magnet and a spring that is driven by recoil and stores the energy in a capacitor. If you carry it, it will also charge the capacitor just from your movement and just shaking it a few times should charge it up if you pick it up from storage.

        And once you have electricity in the system, you can use it for all kinds of things. How about a flip up red dot sight by default that seconds as a safety?
        If you have even more energy to spare, how about magazines, that don’t run on springs but on electric actuators? You could design a multi-column magazine that is actually one long channel that snakes the rounds through in hairpin turns, and then you have two openings, one to get a round out, and another to put the spent casing in again. Having no ejection would be especially helpful in bullpups.

        • aka_mythos

          The idea of having surplus power has its appeal but introduces downsides. If the firearm gains enough charge from each cycling of the weapon and stores it in a capacitor it will always have enough power short of a systemic failure. Surplus power means you’re adding the weight of batteries and the means of housing them.

          In a more advanced system with enough power generation and an integrated battery you’re right, you could more easily incorporate features like powered rails or just integral power hookups for lights and lasers.

          I think magazines are another solution for housing a battery in the absence of a recharging system or firearm integral battery.

          As far as crazy magazine go, there have been cassette magazine but with many of these strange magazines the added capacity never made up for the added weight. Drums and rotary magazines are the only things that have managed to get around that, but they tend to be too costly to be disposable items.

        • comatus

          The Turbo-Encabulator.
          (1)You’re going to want one hell of a reliable kill switch on that capacitor. Once it’s charged, the “air gap” won’t do it.
          (2) New source of green energy. Eligible for govt grants!

    • Zaro27

      Piezoelectric trigger. Each pull generates a charge. Not enough to run the gun by itself, but better than nothing.

  • thedonn007

    I want one, just waiting for the price to come down. It would need to be cut in half for me to seriously consider buying it. But I do want one.

  • SP mclaughlin

    It seems redundant but I want to see an electronic DAO pistol now
    Or revolver with some sort of electric trigger for double action use.

    • Bradley

      I believe the main benefit is the excellent trigger pull. Since it isn’t mechanical it can basically any pull weight you want with virtually no creep or overtravel. With doa it would just add the need for a power source without adding any benefit.

  • Martin Grønsdal

    Make the bolt run a dynamo, as backup.

  • Anomanom

    I don’t really get this for a 22, except as a gimmick. However, if it is reliable, it would be some hot ish for sharpshooting/sniper rifles.

  • c4v3man

    As cool as this is, It’d be more interesting if it was an upgrade trigger kit for existing bullpups. Beyond the fact that you don’t have to deal with designing a reliable firearm around your trigger system, you also have the ability to put the factory trigger back in if needed. That being said, I believe electronic triggers are only available/legal in manually operated (aka bolt action, or single shot) actions, so this would be the first semi-auto electronic trigger I’m aware of.

    Heck, I’d pay $200 for a semi-auto trigger actuator that would allow you to turn a standard AR/AK style rifle into a bullpup of sorts by simply having the electronic trigger actuate a servo to operate your standard trigger. But since the ATF thinks using a string on your trigger constitutes a machine gun, I’m not holding my breath.

    • Anonymous

      Some examples of legal semi-auto guns with electronic triggers include the Pardini SP1-E (Electronicca), the MatchGuns MG2E, the Walther SSP Electronic, and a few others by Morini, etc. These are the semi pistols that do well in Olympic Rapid Fire Pistol. They all have 1kg pull weight setting, but very short travel, no post-break travel, very repeatable, and you can dry fire in your hotel room without ammo.
      ATF is very clear – if it is one-shot-per-function, it is a legal semiauto.

  • Bradley

    I always find it funny that people are so quick to dismiss anything electronic as impossible to make reliable. We live in an age where electronic sights are the norm in the worst and most serious conditions. Obviously things like electronic triggers are still in relatively early development, but as the years go by who knows what potential they could have. The basic operation of modern firearms hasn’t fundamentally changed in over a century. It may not change for another century, but eventually it will.

  • Ann

    I can’t help but think that it’s in electronic trigger configurations like this where the double-tap system (one shot on pull, one shot on release) would really shine. Mostly just because it would add little in the way of complexity to the design in comparison to current mechanical systems. I have to imagine that the most complex aspect would be incorporating a sensor to prevent hammer release on an open bolt, but even this should be relatively easily in an electronic system. Think of the rate of fire…

  • valorius

    No thanks.

  • CavScout

    I’d make it recharge via wind. Then you unhook the sling from the front of the gun and swing it around in circles by the sling. Recharged in no time.