Not Just Metal Anymore: 3-D Printed Fire Control Groups

Freedom Printing 3D (a channel I recently discovered) posted up a video early last month of a 3-D printed fire control group for the AR-15. I was surprised to see it, as my currently industry affiliation has always used metal parts – which prejudiced me against polymers in some capacities. It seems I should have looked harder at polymers which seem to be now functional as a fire control group straight off a 3-D printer.

I am left to wonder… how much actually needs to be metal on a firearm outside of the barrel and bolt? How so will we get to that point?


For a non 3-D printed version, you can check out New Frontier Armory’s Polymer Lower Parts Kit.

Nathan S

One of TFB’s resident Jarheads, Nathan now works within the firearms industry. A consecutive Marine rifle and pistol expert, he enjoys local 3-gun, NFA, gunsmithing, MSR’s, & high-speed gear. Nathan has traveled to over 30 countries working with US DoD & foreign MoDs.

The above post is my opinion and does not reflect the views of any company or organization.


  • Nicks87

    Awesome! I think the guys that are doing this stuff are modern day patriots and are at the forefront of the freedom movement. So what if big govt wants to regulate firearms, we’ll build our own.

  • northafrican

    next thing you’ll hear is a 3D printed barrel

    • abowden

      We can make them and we HAVE made them. Unfortunately, they are universally terrible and nothing can change this until consumer metal printers come around. anything that comes into contact with the cartridge, bullet, or vented gases really does need to be metal. We can make sure the metal parts are as easy to produce or obtain as possible, but we cannot do much more than that as yet.

      • nova3930

        Yerp. Only a matter of time before the metal printing methods become economical though. I can remember not long ago when 3D laser sintering was a million dollar machine. Now it can be had for <$100k. Still not cheap but it's getting there…

        • AmalekHaman

          Yeah, an Aussie company is coming out with a $25k one!

    • nick ootes

      3D printing the tools needed to make a barrel would be a better option

  • Steve Truffer

    Firing pin needs to be metal. Too much flex or distortion otherwise. That flex is good for dissipating energy in a receiver or in furniture, but when squishing metal, its hard to beat more metal.
    Besides, where are you that you cant get a flooring nail and something to take the point off?

    • iksnilol

      Maybe we want our Glock 7s?

      • noob

        good point – if there was 3d printing filament that had unfired clay in it, you could bake the part in a kiln and maybe get a ceramic composite part.

        if it wasn’t too brittle, it could be really interesting…

  • Joel

    One issue that I’ve always been curious about with the 3D printed lowers is the rear section for attaching the receiver extension. This is the definite weak point with the early designs and we’ve seen more material added in this area to re-enforce this junction. It seems to me that it would be best to make a one-piece lower and extension/stock. Maybe something along the lines of the Cav Arms polymer lowers. The only problem that I see with this type of design would be that many of the 3D printers being used are relatively small and may not be able to handle such a large piece.

    • lol

      Has to be two pieces, the stock must be removed to install/remove the buffer spring/ tube. However, if someone came up with a new way to do this (A locking nut inside the receiver maybe?) this could work.

      • Paladin

        The buffer tube can fairly easily be made integral to the stock/receiver.

        • mig1nc

          Yeah, I wonder how they put it in a Cav Arms lower since it is all one piece?

      • Phillip Cooper

        And yet, Cav Arms made a one piece lower in poly, so it clearly doesn’t “have to be two pieces”.

  • Isaac Newton

    Check out the fire control group on the AUG and FS2000. Polymer hammer, sear etc

  • noob

    Why has metal injection molding not been reconfigured for additive manufacturing yet? Instead of a liquid slurry of metal, you could have a filament with metal particles in it that you sinter in a kiln to make a part with similar properties to an MIM part. Yes everyone hates MIM but it is stiffer than plastic.

    • AmalekHaman

      Why does everyone hate MIM? I think you have a good idea.

      • noob

        MIM parts are difficult to sinter correctly Colt 1911 MIM sears are said to be hard and precisely made. Other people may bake them incorrectly and end up with a spongy brittle part.

  • lowell houser

    Great. Now is anyone working on homemade shell casings? Brass or mild steel? How about commercial spec primers? Does anyone have a recipe for a medium burn rate smokeless powder they want to share? How about basic hand operated bullet swager that can be built from scrap?

    People don’t kid yourselves. Making a gun and even working mags is great, but it’s only half the nut cracked. If we are dependent on large companies for ammo we’re screwed.

    Being dead serious, until we have easily obtainable guides to do all of the above AND to build an entire rifle by scavenging from, say, an automotive junkyard, they still have us.

    • AmalekHaman

      Exactly. Barrel and primers are the hardest to make underground.

  • thetruth

    What a waste..I was hoping for a KA-Boom.