The Next Phase: 3D Printed Imura Revolver Hybrid Development

An innovative 3D-printed hybrid revolver design is being worked on as tribute to 3D printing’s first martyr,  Yoshito Imura. Imura was arrested for printing some plastic, blank-firing guns in Japan. The new design would fire from the bottom of the cylinder, as did the original blank-firing plastic gun.  The new revolver has hybrid features, including a steel barrel liner and chamber sleeves . . .

As seen in this computer image of the developing design, the revolver is meant to be double action; that is, one pull of the trigger will rotate the cylinder, cock the striker and release it, firing the charge, whether it’s cap and ball, blank cartridge, or conventional round.

It is an ambitious design. Here is a link to tweets on its development by WarFairy, Frostbyte, et al. Double action revolvers are more complex than single action models such as the original Imura design. I see one weakness that the designers have probably noticed.  There is very little tensile strength in the proposed design.

Conventional revolvers use a metal frame to contain the forces generated by firing a charge. The chambers contain the pressure at right angles to the barrel, but the frame, chamber, and case – if one is used – must contain the rearward pressure. The projectile contains the pressure to the front, where the force is used to propel it out the end of the barrel.

If I were designing this revolver, I would consider the use of a bolt as a center pin for the cylinder to turn on.  A simple backplate of steel could be made to screw the bolt into, adding tensile strength.  It would not need to be circular, as long as it supported the rear of the chamber being fired. Removal of the bolt would allow the cylinder to be removed from the side of the design, so as to facilitate loading. Many conventional revolvers use this design feature.

While development is still in progress, at least one prototype cylinder has been produced. Looking at the surface of the cylinder, it appears that a hobby-type printer was used. More images are available here.

Hybrid designs such as this offer unique advantages for the production of inexpensive firearms outside of normal channels of commerce.

©2014 by Dean Weingarten: Permission to share is granted when this notice is included.

Gun Watch


  1. avatar KnowWhatIamTalkingAbout says:

    Is the squared out portion visible in the grip where the smart gun tech chip goes?

    1. avatar Peter says:

      i think the smart gun chip will go into the shoulder thing that goes up, but i’m not seeing that here

      1. avatar lolinski says:

        They will probably use that square hole in the grip to attach a stock. Could also put a battery pack there (probably need to be bigger for that) and a flashlight or laser above the barrel (partially removing that weird thing above the barrel).

    2. avatar Stinkeye says:

      Those two big square hunks are probably for metal chunks so that the thing isn’t illegal under the ridiculously stupid Undetectable Firearms Act. The one in the grip may just be for ballast, so the gun has some semblance of balance.

    3. avatar GS650G says:

      This should easily go 200 rounds per minute on full auto.
      Available soon at Walmart just in time for Xmas!

    4. No, that’s where the chunk of legislated metal must be placed in order to meet the Undetectable Firearm Act of 1988 and 2013

  2. avatar Anonymous says:

    I keep waiting for a 3d printed shotgun. One could use a steel pipe from the hardware store plumbing section as the barrel.

    For 3d printed revolvers, I would seriously be worried about cylinder alignment.

    1. avatar KCK says:

      wide mouth forcing cone, Self aligning

    2. Inexpensive revolvers solve the problem with generous forcing cones. The rear of the forcing cone on the RG 14 that I tested back in the 80’s (after the Reagan assassination attempt with an RG-14) was about .32 inches! Also, 3D printing is relatively precise, allowing for decent alignment. It is not hard to determine if the chambers line up without actually firing the revolver.

      1. avatar Anonymous says:

        What was the chambering? 22LR?

  3. avatar Hannibal says:

    Cool. I’m not going to be the first one to fire it, but still cool.

  4. avatar KCK says:

    Good point on the axial forces generated with the pressure behind the bullet in the barrel against the cylinder. Easily handled with your bolt idea at least for a .22

    1. Considering it further, if you used a bolt with sufficient thread to clear the cylinder, you could use a large washer as the back plate, with another washer and just a nut on each end of the cylinder. You could use a hacksaw or drill to make slots/holes to allow the firing pin to access the primer. Then the backplate would be removed for loading and unloading. A nut and washer in the front of the cylinder provides for a way to tension the backplate and to allow the cylinder/bolt/axis to turn easily. Cylinder-barrel gap could be regulated by the bolt as well.

  5. avatar Noishkel says:

    This is a nice development. 3D printed guns are a good concept. But they’ll still need good metal barrel and bolts.

    1. Next thing you know, the elites will not allow the masses access to metal working tools…

      1. avatar Noishkel says:

        Oh if they could make it stick I guarantee they would do just that. To get back in line with the original story they’re already talking about the need to regulate 3D printers to prevent this very thing. Unfortunately for the powers that be it’s too late to put the genie back in the proverbial bottle. The maker community has been building home made versions for years now. And while the printer head is still kind of pricey they’ll only get cheaper and better.

    2. avatar Marine 03 says:

      You may be surprised by the strength of new polymers that are being developed. Steel construction will be favored but plastic firearms that can fire 200-300 rounds before becoming unsafe are nearly a reality now. No metal needed. They are disposable and when worn out you just print a new one.

  6. avatar Neil D says:

    Great point Hannibal. I would not be the first to fire it either. In fact I would probably never fire a pistol like this. Don’t really see the point in being a test dummy for something like this. Guns like this may eventually viable weapons but I will wait for others to find out before I try them. Could be that it fires the first 50 rounds fine and then blows up in your face. Who needs that? For now the SCCY fits my needs for an inexpensive, reliable pistol.

  7. avatar TheBear says:

    Can’t stop the signal.

    1. avatar Raul Ybarra says:

      Everything goes somewhere, and I go everywhere.

  8. avatar Hoots says:

    That looks like a great EDC piece.

  9. avatar Gunr says:

    I,m still waiting for my printed 30MM chain gun plans!

  10. avatar racer88 says:

    I see it fires from the six o’clock position of the cylinder like my Rhino. 🙂

  11. avatar Rokurota says:

    Looks to be .9 mm.

    1. Looking at all the pictures, I believe the prototype cylinder is made in .22 rimfire, or 5.6x15R.

      1. avatar Carry.45 says:

        If you took that seriously you just lost all credibility with me. That said I really enjoy your writing.

        1. Thanks for the kind words. The .9mm just begged for the metric .22 LR designation!

  12. avatar Larry says:

    You would be amazed what a good machinist can make with just access to a decent lathe… Add in a simple manual milling machine like a Bridgeport and the scope of guns that can be made in a basement or garage shop is huge…

    Surprisingly it is things like magazines that can be the hardest to make even if you make a simple sheet metal folding brake. The rifleing bench can be made with simple woodworking tools and plenty of plans for single cutter types as are still used for fine guns are abundant. High pressure button rifling is harder to set up in a small shop of course. The easy access to precision barrel relineing tubes from places like Brownels has ment for the guns I build for myself I have not had to use the riffling bench I made for my first flintlock about 50 years ago.. But it’s parts are there in the corner of the shop should I decide to try to do it again… I have a slight hankering to try gain rifleing for cap lock bench rifle, so I might to it if I live long enough. Repair work on friends guns means that my project list seemes to grow faster than it is trimmed by completed projects.

    1. The magazine situation is one of the reasons I found it significant that magazines (less the springs) were one of the first and most successful items printed by 3D printers.

      If you an print pretty good magazine bodies with feed lips, and followers, the rest is much easier.

      A simple slamfire subgun becomes very simple.

      1. avatar Anonymous says:

        A simple slamfire subgun becomes very simple.

        They should print these next.

  13. avatar Dr. Kenneth Noisewater says:

    Please post a torrent (or magnet) link when available, I’d like to add it to my collection of plans..

    1. avatar WarFairy says:

      It hasn’t been released yet. I’m holding off on wide release until testing has been conducted.

  14. avatar Geoff PR says:

    Hey, Dean –

    Are there any commercial revolvers that use that type of cylinder timing?

    1. Mauser Zig-Zag revolvers:

      No longer made. Quite collectible, I would think. I would like to have one.

      The Webley Fosbery is better known. The cylinder is much the same, but it was one of the rare semi-automatic revolvers.

      They would not fall under the GCA 1968 rules. Antiques.

  15. avatar Former Water Walker says:

    Cool. What’s next?

    1. I doubt it is going to happen, but if it were me, I would be designing an electrically fired four-shot dart gun that used an optimized propane/butane with oxygen mixture as the propellant. The propellant would be stored in the hollow darts, which would themselves be 3D printed. The four dart barrel assembly would be about seven inches long.

      This would be a muzzleloader.

      I should probably write up the idea as an article.

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