WarFairy’s Latest Additions To The Charon Line Of Printable AR-15s

3D Printer-extraordinaire WarFairy has expanded his P90-styled Charon printable AR-15 lower from a single design into an entire line of printable rifle and pistol lowers.

The original Charon receiver design has been upgraded to version 0.2. The updated model features a thicker magazine well with a finger hook (I am sure someone more knowledgable than I can explain in the comments below what finger hooks are for … ).

The most exciting new addition to the Charon line is the Carbine, Adjustable Stock. The stock on this model slides out from under the buffer tube to adjust the length of pull. The length of pull is adjustable from 11.3″ to 14.4″.

Carbine, Adjustable Stock, Mockup

There are now two Charon pistol models. The first is the unbuffered model (pictured at the top of this post). Lacking a buffer tube, this lower requires a bufferless upper receiver. It would work with a Rock River Arms LAR-PDS Pistol upper (although the uppers are not sold separately),  Faxon Arms ARAK-21 upper or a standard pistol upper with a CMMG .22LR Conversion kit installed.

The buffered lower version of the Charon is suitable for regular buffered uppers. If anyone knows of commercially available short buffer tubes that are reliable, let Warfairy know in the comments so he can create a shortened version of the buffered upper.

Buffered Pistol Receiver

Wairfairy has also created a modified version of the DefCad v5 AR-15 lower. It incorporates his magwell strengthening.

AR-15 Receiver


The Fairy has told me he is hard at work on his next release. He is looking at making a bullpup AR-15 lower receiver inspired by the long-awaited but never-delivered Magpul PDR.

The Whole Family

Send Space are hosting the printable model files. Print away! (where legal to do so).

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.


  • looking at the location of the finger hook, it would be used by your forehand( support hand) to help steady the rifle…..much like the way we did using the magazine and magazine well when shooting off hand

  • William

    Those designs are pretty cool, to be honest I wouldn’t mind paying for a polymer one though, hopefully he get enough funding to expand his ideas.

  • gunslinger

    you can’t stop the signal

    • schizuki

      Killed me with a sword, Mal.

  • Anderson Keim

    Now, the earlier charon had a series of interchangeable fore-grips. Why were those removed? Structural reasons? I really liked the idea of a P90 style fore-grip on an AR-15.

    • Juice

      An Imgur album was posted to Reddit’s /r/guns subreddit yesterday which showed this lower with the P90 foregrips. So I think they’ll still be available.

    • WarFairy

      Yes, the interchangeable grips were removed in favor of the finger hook front end due to a breakage suffered by one of the beta testers. I will be releasing the Foregrips as rail mounted accessories soon though.

      • Anderson Keim

        Yay! Also, thank you for creating and posting these designs.

      • FourString

        Hi Warfairy,

        Could you guys also work on a lower that enables one to use a Remington 870 Magpul stock on a buffer-less AR (a-la-ARAK-21) upper? 🙂
        A traditional sporter stock would be great!

        Would be much appreciated!


        • WarFairy

          I’ll be working on a project for a cali-legal stock based on the AR once I’m done with the Bullpup. The running joke of anyone that hears about it is the “FUDD-15”, but hey, there’s a need for it.

          • FourString

            SWEET. looking forward to hearing more :]

  • JumpIf NotZero

    The sidling stock is pretty clever.

    I look forward to seeing what come up from a bullpup style. If it looks good enough, I expect someone to start making production ones as that’s an untapped “desirable” if I’ve ever seen one.

    LAN World / HERA Arms would be the likely candidate to take something from 3D printing and make a run for a US Market…. Coming SHOT 2014

    • Suburban

      I thought so too, but I could live without the thumb-hole grip.

  • Bull

    why does he need a buffer tube? its intergreated in the stock after all?

  • Ian

    Still appears to suffer from the same problems as his last one posted on here. Except for the non buffer version. That one will just tear its pivot pin out constantly.

    • WarFairy

      Tests of a similar lower with a standard diameter rear pin (though a straight pin was used rather than a captive pin) in .50 Beowulf showed no signs of stress fractures or cracking.

      Give me and my beta testers some time before you start dismissing us. We have been underestimated at every turn.

      • Ian

        I’m not underestimating anyone. I’m speaking from experience and trying to give you advice.

        • WarFairy

          The reason the older versions of the lowers were tearing the rear pin out was a combination of spring and camming happening under recoil. There was just enough give in the magwell for the entire upper to move rearward between the time the round was fired and the bolt unlocked. Due to the radius at the rear of the upper, and the entire upper sliding back, that radius on the lower acted as a ramp, pulling the upper upwards and back. This led to a lot of stress upwards on the thinnest part of the lower receiver, and once that top arc gave way, it was free to move rearward even further, flexing the stock tower back, and the stress fracture propegated down to the corner of the pistol grip.

          This design disallows that initial rearward movement by massively strengthening the magwell and the rear tower by incorporating the buffer tube. Beta tests are ongoing, but I am confident that it won’t be an issue.

          Plus, if it is, I’ll release an update.

          • Ian

            I never once said the takedown pin was going to be a problem.

      • housertl

        In light of the ability to handle the more significant recoil, do you think that a printable, bullpup, ar10 lower could be functional?

        • WarFairy

          It absolutely could be, but the problem lies in finding yourself an upper that is both Bufferless and in the AR-10 pattern. It’d likely have to be a custom job, and I’m trying to keep everything as “off-the-shelf” as possible.

          • housertl

            AH…so your bullpup design will be for bufferless uppers, like the ARAK-21? Nice.

  • Edgar Castelo


  • Zebulun P Messerly

    How are you supposed to install the safety and safety dentent on the fixed grip lowers ?

    • The same way you do in the cav arms ploymer ar15 lower load the spring and detent from the top

    • WarFairy

      From the top rather than the bottom.

  • J

    Know what would be really cool? If they did a Magpul FMG-like project (even if it used some Glock parts).

  • Patrick

    @warfairy : have you done a test print of the grip sections yet? The P90-style grip doesn’t look very ergonomic.

    • WarFairy

      One of my Beta testers has completed a print of the V0.1 with the P90 foregrip without the knuckle guard or rail. Initial reports are positive on “feel”, but we’ll know more once live fire testing gets under way.

  • Tenacious221

    The mag well is probably the part of the AR that least needs reinforcing for 3d printing.

    And as the universe would have it, it’s the easiest place to make stronger :). Oh well. Guess ol’ Eugene Stoner is trolling us 3d printing fans from 50 years in the past!

    • WarFairy

      Unfortunately one of the beta testers did suffer a breakage at dead center front on the magwell. I suspect that the printer was improperly calibrated and combined with an old surplus aluminium GI mag to cause the breakage, but I wasn’t taking any chances with a failure that close to the front TD pin.

      We’re still working the bugs out, but V0.2 is looking more promising.

  • That collapsing stock one is pretty neat. Just a note regarding buffer tubes. The Cav Arms lowers, which incorporated the stock into the lower uses a carbine buffer and spring. The buffer “tube” is just the hole in the stock.

  • GlockLove

    How about a 3d printed Slid fire stock !!! i know everybody is tired of the 350$ price tag on the ssar !!!

    • WarFairy

      I won’t be making a Slide Fire stock based on my own perception of them, but there is nothing stopping anyone else from designing one to be printed.

      • GlockLove

        vary true but there’s a big market for another slide fire type stock and money to be made. U could even cut the price in half. Retail it for 175.00$ and still be ahead after cost of printing

  • dranor44

    i need to finsh building a 3d printer of my own so i can make this!
    so epic

  • dranor44

    what type of plastic grade did he use and what brand 3d printer?

    • WarFairy

      Three versions of my lower have been printed on various cartesian 3D printers, each using ABS as a material. I know one full V0.1 Charon was printed on a Cube, and one Hally Edition Unbuffered pistol was printed on an Ultimaker. The third is unknown and still under way.

  • Cuban Pete

    “Print” your own lower for personal use. No need to deal with the authorities!!

  • cutamerc

    Thank you to WarFairy and all involved. Keep up the good work!

  • me

    As a practical matter, this and the bullpup version sound fascinating, but I personally will wait until either 3D printers can work in fiberglass reinforced structural nylon blends like Dupont Zytel, or someone offers a fiberglass reinforced polymer model commercially.

  • Trent DeRoc

    “You are free men, act like it.” – WarFairy

    It goes for posterity.

  • buckshot35211

    I would love to get the bufferless model, as the ARAK-21 has really caught my attention. Imagine a bullpup with the ability to switch between 5.56, .300 AAC, 6.8, or any other intermediate caliber!
    Well done, WarFairy. I always enjoy seeing innovation in the firearms industry