Homemade Bullpup AR-15


It might not be the world’s perfect bullpup design, but it does show what a shooter can do with a little imagination and a few hack saw blades.

Although some may question the usefulness of this experimental design, the idea of moving the bolt over the shoulder is an interesting one.

Thanks to jhdudt for the tip.

Richard Johnson

An advocate of gun proliferation zones, Richard is a long time shooter, former cop and internet entrepreneur. Among the many places he calls home is http://www.gunsholstersandgear.com/.


  • David

    A catastrophic failure puts the chamber right next to the head. Thanks, but no thanks.

    • Buxy

      Has anyone actually seen a well documented example of this happening to the countless AUG’s, Tavors, and L85’s, just to name a few, that have been fielded around the world? You’d think we’d have heard about one by now. I’ve seen plenty of pistol kabooms and yet the loss of a hand is apparently less frightening to the masses than the mythical, “bullpup decapitation.”

      • fjkhoury01

        its not really possible or common with all those bullpups because they are piston designs its a very real problem with DI guns note all the catastrophic explosions caused by out of spec ammo that result in tearing of the upper receiver in ar15s.

        • TCBA_Joe

          No. Just no.

          The amount of well documented catastrophic failures of DI ARs over bullpups is due to the shear number of DI ARs out there. I would bet Bushmaster (1 of ~260 AR15 companies) alone sells more AR15s in a year than the combined total number of Tavors, AUGs, FN, and misc bullpups made in the same year.

          In my picture reference library I currently have 2 well documented bullpup catastrophic failures.

          As for the issues sourrounding the “ka-boom” with a bullpup, those designed from the ground up as such typically have failsafes like an steel plate to redirect the blast downward from the shooter. This doesn’t exist in the AR URG.

          • Tinkerer

            The third most widespread assault rifle in the world is a bullpup: the AUG. 37 years of use by lots of military and police forces in some quite harsh environments, and you would think that someone, somewhere, sometime, would have mentioned something about catastrophic failures.
            And about your two well documented cases: the scientific word for that is “anecdotic evidence”.

          • bbmg


          • Tinkerer

            Thank you for pointing and correcting the mistakes I make while writing on english, my non-native language. 🙂

          • Cymond

            The original question was “Has anyone actually seen a well documented example of this happening to the countless AUG’s, Tavors, and L85’s, just to name a few, that have been fielded around the world? ”

            TCBA_Joe mentioned that yes, there have been a few well-documented cases. He never stated that it was a complete listing of all data, but only that such things have happened and been documented.

            You are right, the plural of “anecdote” is not data. Anecdotes are not necessarily representative of the whole. However, if you reduce a set of data down to a single point, what you have left is an anecdote.

          • Random Person

            The AUG is used by a handful of small nations with little actual combat experience. The only real user of note is Australia. In the US AUGs are uncommon to say the least, and I doubt many of them are shot much. Of course there are not going to be photos of numerous blown-up ones to be online.

            To expect Steyr to publicize incidents would be naive at best.

            Some people apparently believe that a lack of evidence constitutes negative evidence?

            More to the point, the bullpups mentioned were all designed from the start to be bullpups and they do no feature two-piece receivers of relative thin and brittle aluminum where the user’s face will be resting.

      • n0truscotsman

        Nope never heard of one.



      • Random Person

        I’ve seen more than one AR15/M16 upper that was destroyed by a out-of-battery firing.

        Would you care for this next to your face?


        This chunk of receiver would have been much easier to find if someone had had their head in place to catch it:


        Likewise this one:


        Bullpups are an answer in search of a question. Everything they gain in compactness they give up in poor ergonomics and increased exposure of the user to return fire.

    • SP mclaughlin

      Fear of bullpup explosions is like fear of flying imo.

  • ColaBox

    I think Killzone 2 represented this as best a possible.
    AR15/L85/LR-300 were used as the design inspiration.

    • Dr Sick

      All killzone weapons are pure beauty !

    • mechamaster

      Ah.. It’s missing the grenade launcher module.

  • guest


  • 1leggeddog

    This is definitely a decent starting point to engineering some kind of bullpup kit which would be attached to the Upper and not the lower.

    in fact, his idea of keeping the buffer tube for ARs that need it over the shoulder is totally doable. You would have to design a new stock which would attach itself to the lower’s pitol grip and feature a kind of half-moon that you could put over your shoulders.

    The bullpup kit would replace the handguard but attach itself to the upper’s screw and go directly to the trigger like he did with the hacksaw blade.

    • LCON

      He should have mounted a rail cover behind the rear sight to act as a cheek rest. It also would likely have directed some of the gasses away from his face.
      looking at the rig I am reminded of a AK based Bullpup conventional hybrid rig video. The builder of that system kept the original controls but also rigged up a bullpup set and could switch back and forth between them as needed.
      altering the rig up you describe 1leggeddog if the pistol grip was flatter in angle with a pad running along the back of the lower. Mount a abbreviated buffer tube and a stock like the one Colt developed for there sub compact carbine. use a AR with a forward mounted charging Handel or both forward and traditional. Devise a mechanical action that like the video rig allows the forward trigger to actuate the rear mount a trigger guard and pistol grip that could pull double duty as a fore grip with a hand stop. Mount a front sight a flip up iron just forward of the receiver on the top rail, a rail cover just behind that and a second backup iron at the rear of the receiver, if you want optics a HWS or red dot in the forward position. You might have a carbine that could pull double duty the user being able to decide whether they want to shoot bullpup or conventional.

  • I’ll stick with my sexy non-bullpup AR-15. 😉

  • mechamaster

    It’s awkward to reach the charging handle.

    • gunslinger

      i don’t think ergonomics were a high priority on this build.

    • Cymond

      Plus, reloads & malfunction clearing are always less than ideal on a bullpup. For many people, a single magazine should be enough to handle a defensive situation, and the problems with reload speed aren’t a problem when shooting recreationally.

  • Blastattack

    I think it’s pretty badass. I always wanted a Barret M82A2 clone in a smaller and more affordable package.

  • LCON

    Isn’t the Iranian KH2002 A Bullpup Bastardization of a Chinese Abomination of a AR15?

  • ChrisK

    So if I put this mod on a registered AR pistol (with no stock attached to the back of the shorter buffer tube as it is now), would it still be considered a pistol with the grip moved forward and no defined shoulder rest? It would certainly make an SBR nice and short!

    • wetcorps

      It probably counts as a SBR since you can shoulder it and actually aim like this.

      The Draco kit from CBS isn’t a SBR, if I understood well it’s only becase you can’t really get a cheekweld with it.

    • gunslinger

      from my understanding (see the SS “arm brace” device. not sbr as it’s not intended to fire from shoulder) you “should” be ok. as the pistol would then be meant to fired from the front pistol grip (no PG in the back). although i’m not sure if the AFG would then be the no-no for a pistol.

    • Gary from Michigan

      Does anyone remember the Bushmaster Arm Pistol?. It was a legal bullpup pistol.

  • John

    LOL. That 20 cent rubber band is faster than a $500 Taccon 3mr.

  • Lance

    Waste of time Bullpups suck stick to my regular config rifles.

    • Gordon

      blah blah blah

      to each and everyone

  • Christopher

    Two flavors that don’t go together. As you lose the reliability and accuracy of a gas piston by going with a DI system. It would be impressive if he can get it to be HK416 style short stroke.

    • MichaelZWilliamson

      How do you figure piston guns are more accurate than DI?

  • gunslinger

    i can see why people poo-poo this. yeah it’s stupid. but.. i think “the wood has holes for tactical ventilation” pretty much gave this away as a “i’m just goofing around”

    i do like the fact he spent time to figure a working proof of concept here. i’m sure in time, a better conversion kit could be had. but i also think it’d be better to just use a traditional bull pup rifle from the start.

  • Nomad

    This seems very similar to a technique I’ve read about the USMC using with their M16s called “ShortStocking” in which the buttstock is put on top of the shoulder and the pistol grip is used as an improvised buttstock. It is used in confined spaces where having more rounds downrange faster is preferred to more accurate fire.

  • Tuulos

    The biggest problem I have with that idea is the simple fact that the recoil impulse isn’t directed straight into the users body but over his shoulder.

  • Gary from Michigan

    Wouldn’t be a bad idea to use am Extar EXP-556 pistol as starting point for a bullpup AR.

    No buffer tube.

  • Leigh Rich

    Too much time with nothing to do?

    • Gordon


      • Leigh Rich

        You said it sister

  • Michael

    I like it. Magpul are you listening?

    • MichaelZWilliamson

      Yeah, but they’ll have Bushmaster build it.

  • Mahhn

    It’s more that “short” to be a quality bullpup, like my RFB, which is sweet.

  • Troll123

    Haha wait your name is Dick Johnson !!!!!