AR-15 Bullpup Conversion by Center Balanced Systems

Center Balanced Systems is working on a prototype of a bullpup conversion for AR-15 style rifles. The bullpup rifle is called CBAR. Anytime you hear the words “AR-15 bullpup” the next logical question is “what will they do with the buffer tube?”. In the case of CBAR, it is left as is. The buffer tube goes over your shoulder and the actual stock which contacts the shooter’s shoulder is in the area where AR-15 pistol grip is normally located.

They will most likely use Anderson Manufacturing rifle as a base for the CBAR bullpup. However, it is not clear if they will be selling complete converted guns only or they’ll also offer a conversion unit. There’ll be also several modifications of CBAR with different foregrip options adding $40 and &60 to the cost of the basic rifle. The MSRP is not specified yet.

CBAR bullpup - 2

Center Balanced Systems has sent samples of the prototype rifle to several different people for testing and evaluation. Below is a test firing video of the CBAR rifle:

A similar system of the recoil system extending over and behind the shoulder was earlier used by Barrett on their M82A2 anti-materiel rifle.

CBAR bullpup - 1

Also, a couple of years ago, the host of DemolitionRanch YouTube channel has released a video, where he made a similar homemade conversion:

I think this concept could be more useful if it was possible to quickly convert the gun back to its original configuration. Imagine if it could be done as fast as folding the stock on other rifles.


Center Balanced Systems
Address: PO Box 35851, Phoenix, AZ 85069
Phone: (602) 434-9117

Hrachya H

Being a lifelong firearms enthusiast, Hrachya always enjoys studying design, technology and history of guns and ammunition. His knowledge of Russian allows him to translate and make Russian/Soviet/Combloc small arms related information available for the English speaking audience.
Should you need to contact him, feel free to shoot him a message at


  • CBRPS only sells conversion kits, not whole-up guns. I don’t see any significant reason that would change with ARs.

    The kits are… interesting, but not what I would consider a polished product. Bought one of their Mosin options from about four years ago, and the 10/22 version recently.

  • Jake

    Can I put a tac sac on it?

    • Rick O’Shay

      Only if any cupping done is inadvertent, and not intentional.

    • Sasquatch

      By the looks of it you could use one as a face stop.

      • Jake

        As long as it isnt the size of sasquatch nuts ill be ok

      • jono102

        Don’t you mean chin stop.

  • Blake Allen

    Just throw an ARAK-21 upper on there, no problem.

  • Mnor

    Good God, that thing is ugly.

  • GD Ajax

    Instead the gas going into the barrel, it can now go into your face!

  • Evan

    What about the charging handle? Unless your rifle has some kind of forward charging handle like Adcor puts on their rifles, this bullpup conversion seems like it would make charging needlessly complicated. And even if you do have an Adcor, does this kit even work with the forward charging handle?

  • JustAHologram

    Two things that look like they could be improved; something to minimize that buffer tube like a PDW kit or something similar and a side charging system

  • Blake

    You could almost call this a CARl-15…

    • noob

      need one of those blank firing T-shirt cannons

  • Vhyrus

    So… WHY would I buy this over a Tavor, again?

    • Ryfyle

      Better yet, A Keltec RFB. That thing looks like the last thing to be said For working Bull-pup design.

  • noob

    oh my god they finally did it. if I was in a place where you could make gun accessories, I’d call my version twice as ugly and call it the AR-bomination.

  • noob

    Hey guise, guise! what if… we made the buffer tube go down under your armpit so the rotation pulls the muzzle down? aiming could be done with one of those future warrior gun mounted cameras attached to a HMD. The foregrip could be chainsaw style.

    back up iron sights could be flip up on 12″ long metal rods that fold towards the middle.

    You can then mount the gun on a steadycam harness.

  • Joseph Goins

    I wonder if you would be creating a new firearm by moving the controls to a new unit.

  • guest

    What an ugly, meaningless mutant.
    At the VERY LEAST they could have chosen that Korean AR clone, that buffer tube-less one that has a compact bolt. This is just retarded.

  • plumber576

    Jurassic Park said it best:
    “…your scientists were so preoccupied with whether or not they could that they didn’t stop to think if they should.”

  • Yankee

    It appears that recoil becomes more pronounced with this configuration’s alteration of the AR15’s purposefully-designed in-line action, which was meant to keep the moving parts in the same plane and reduce the pivoting leverage against the shooter’s shoulder. By putting the buffer and bolt carrier assembly above the shoulder, and then having both moving so that the end of travel is behind the shoulder, it enhances that pivoting leverage. This is further exaggerated by placing the pivot point (shoulder) more forward, at the normal location of the pistol grip.

    Summary…not a good design. Seems like “Center Balanced” is exactly the opposite of what this system is. A proper AR15 already balances out just forward of the magazine well…you know, in the “center.”

    • JustAHologram

      Which is why even if it runs the cost up a few hundred bucks a collapsible PDW stock that minimises the buffer tube and keeps things in line would be an improvement.

  • Gary Kirk


  • forrest1985

    It says it all really, when the quicky DIY version on DemolitionRanch looks better than something a company has spent time developing! Either way both are fugly bullpup designs, so meh!

  • iksnilol

    Man, it’d make sense if they made it upside down and put the mag behind the shoulder, and then sold it with 200 round double drums or something… preferably in 308. I mean, if it is going to be shoulder-fired in that sense than they should go whole hog.

  • Frank

    Why not use a LR-300 upper receiver?

  • MadMonkey


  • Simon R.

    I own a Center Balance chassis for my Ruger 10-22. Its fun. But their stuff is not refined. Its really a jumping off point for someone that likes to tinker.

  • Winston Behle

    That is one of the fugliest guns I’ve ever seen. The buffer tube kills the shape.

  • ozzallos .

    The buffer tube. My biggest pet peeve concerning the whole AR derivative design. Can’t even make a decent pistol or folding stock (that can fire) with it, let alone a proper bullpup.

  • Elvis

    A bad idea, executed poorly.

    They shouldn’t have done the conceptual drawings in Microsoft Paint, either.

  • Joe Gamer

    I have their kit for the 10/22…
    I don’t really recommend it, the trigger in mine is fubar and I can’t be bothered to spend hours flattening out the transfer bars, it really needs a spring to assist with reset after trigger pull, I have to manually flick the trigger forward after every shot.

  • Joe Gamer

    They should use the ARAK 21, no buffer tube.

  • Chris H

    I’m not one to be mean about another engineers designs. Different Strokes for Different Folks. But I have to ask about TFB’S motivation to put this article up. Are you guys trying to be mean to this company?!

  • JoshCalle

    Why not use any one of the bufferless piston uppers available, like the ARAK-21 or a rock river arms upper?

  • Niguana

    No thanks

  • The Brigadier

    I guess the consensus is this is a pug ugly conversion and no one will buy it. Back to the drawing board engineers.