Semi-Automatic .22 Pistol Design For 3D Printers

Proteus at the DefCad forums has published CAD files for “The Brick”, a 3D printable semi-automatic .22 LR pistol. The gun is mostly made out of ABS plastic, even the bolt and barrel, but it does require a number of metal components, including an AR-15 semi-automatic fire control group, firing pin and buffer spring as well as a Ruger 10/22 magazine spring, a 1x8mm metal insert (for the chamber) and .44 caliber lead bullets or equivalent (inserted into the bolt to provide weight).


As far as I know, this design is theoretical and nobody has actually fired it. Given the venerable .22 round’s rimmed design is infamous for causing feeding problems, I am going to remain skeptical that consumer 3D printers are a practical, and safe, method to produce semi-automatic firearms in their entirety.


Many thanks Eric for the tip.

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • Sulaco

    You can’t down load the files without “signing up” for the site.

  • Internet Browser

    Should have been designed around hardware store springs and other things non-gun related.

    • Internet Browser

      Regardless, if someone makes one and successfully tests it, there will be much bemoaning going on in certain circles.

  • spudro spyrdenstein

    printable pepperbox style solution would probably achieve some level of dependability

    • Internet Browser

      Reload by tossing the fired barrel cluster in the garbage and installing a new one since longevity won’t be a plastic barrel’s strong point any time soon. The chambers can be tight so that ammo won’t just slip out of the spare clusters.

    • Suburban

      Something like the COP derringer, perhaps?

  • abowden

    This gun isn’t entirely 3d printed, It uses an AR-15 fcg, a metal barrel liner, a buffer spring, a firing pin and weights for the bolt. Though they are working on a printable FCG. Don’t worry, fosscad has far more in the works, there is a design for a 3d printed rocket launcher that works in simulations, they are printing the lightest AR-15 lower ever made, (0.71 pounds, it is a buffer, stock and receiver combination)).
    I suggest you download the latest megapack (4.6)
    remember to only click the grey buttons on bay files, or it will download something else instead.

  • xhln

    Looks pretty Tediore to me.

    • Avery

      I was think “Neophyte’s First Bolter” myself.

  • JT

    When are they going to produce designs that make use of readily available metal? pipes, nails, washers, springs, dowels, etc. that can be readily found. They would produce a lot higher quality pieces

    • Kyle

      Google a four winds shotgun if you want pipes and nails.

    • Paladin

      BSP SMG. google it. It can be entirely made out of pipes, pipe fittings and other readily available hardware.

  • Billy___Bob


    Why not a 3d printed launcher and 3d printed projectiles? Fill em with propellant after printing.

  • BryanS

    with a 22 barrel liner, you could probably get some accuracy out of it too.

  • fosscad

    This is a FOSSCAD design by Proteus (a fosscad developer). Defcad is just the search engine. FOSSCAD is the open source group of developers who release these designs. check, @fosscad on twitter. fyi

    • fosscad

      Also check out the developers twitter account @ProteusFosscad 🙂

  • RagTime

    Hello! Random fosscad lurker here, I’ll just answer a few questions.

    -Generally when downloading files on certain sites, there are many fake sign up to download ads or fake click on me buttons. Obviously a direct link would be preferable, but due to the nature of the files, such sites are necessary.

    -We already have a derringer,

    I hope that answers your questions about this! 🙂

    Oh, and we’re short on testers, so if you’ve got a 3d printer, come over to (fosscad is not doing this with Cody FYI, we’re just using the forums), and see what you want to download and try out! If you aren’t eager to try out the firearms, you can still try out the lowers, those are for sure quite reliable.

  • Player_L

    I humbly think 3d printing, as it is now, a hugely overrated technology.

    While fun, it´s slow as hell, uses very weak building materials, and whenever metal is used (laser sintering) the material stress renders most pieces useless for direct use.

    Another huge negative point is that most thermoplastics attain most of their useful properties by mixing with other non-plastic materials (Think fiberglass and nylon to make weapons-grade Zytel), which most definitively cannot be extruded through the nozzle of the printer.

    I think additive 3D processes have a lot to offer, but they´re not quite there yet.

    Besides, why someone with the funds and technical expertise needed to build and operate such a machine wouldn´t be able to procure a more effective weapon by other means is beyond me.
    Homemade gunsmithing is nothing new, and hasn´t changed much since the ´50s.

    You could either make a pipe-and-washers smg or go the distance and actually use a lathe or stamping press to make an assault rifle receiver. The result may be of some use to a criminal, terrorist or insurgent, but it will not, by any stretch of imagination, compare to the reliability and accuracy of a factory-made weapon.

    And you still need to get ammo for it! Most countries where guns are heavily restricted, also make it difficult to acquire ammunition, which is not something you want to make from scratch.

    I guess in some countries like the USA, where you can manufacture for personal use arms you can legally buy, it might be an interesting hobby. Personally, I´d rather keep all my fingers, thank you very much.

    I think 3d gun printing is still a an answer looking for a question.