Soviet AO-63 Experimental Double-Barreled Assault Rifle

I was planning to write about this firearm in the near future but it always was the last one in the list of such firearms (rare, experimental Soviet/Russian guns) to write an in-depth article about. And the reason is the extremely scarce information available about this firearm. This gun is literally something mysterious. However, recently Russian “Kalashnikov Museum and Exhibition Complex of Small Arms” has released a short video on a Russian social media website, which shows this extremely interesting firearm and some of its parts. To my knowledge, this the first time internal parts of this firearm are being shown. Actually, it may be the first time this rifle appears on the internet at all.

The video itself is in Russian, but you can see some interesting footage of this unicorn gun. Further in the article I’ll translate and discuss each aspect of the rifle that became known thanks to that video. So let’s watch the video first by proceeding through the link below:


In 1984, ten years after the AK-74 rifle and 5.45x39mm cartridge had been adopted, the Ministry of Defense of Soviet Union launched trials of a new type of individual firearm. The new gun was supposed to increase the hit probability and be up to twice as accurate as the AK-74. The Soviet trials were called “Abakan”. As you know the winner of these trials was AN-94 rifle by Gennadiy Nikonov. If you want to learn more about the AN-94 click here and here, also watch one of the recent videos by Forgotten Weapons.

As in the case of many other military trials, the winner becomes a more or less well-known firearm and the competitors ultimately become forgotten with very little information left about them. Nevertheless, there are often some ingenious design concepts incorporated in these firearms no matter that they lost the trials. It is also the case with many of Abakan trials rifles.

Images are screenshots from the Kalashnikov Museum’s video

AO-63 was designed by Pyotr Tkachev of TsNII TochMash. Tkachev was already known for a number of experimental concepts like his AO-46. He is also one of the first designers of the balanced action concept (AO-38) and the delayed recoil impulse design (AO-62).

So AO-63 entered the trials a couple of years later (June 1986). As I said, there is too little information concerning this rifle. Even the available information is usually contradicting or varies from source to source. As an instance, in some sources, they say that AO-63 was one of the two rifles that made it to the final stage of the trials (along with AN-94). Other sources say that the rifle was dropped in early stages. So the history of this firearm is still pretty much mysterious. But let’s see what interesting design features it has.

Note the two barrels and gas blocks

The AO-63 rifle is chambered in 5.45x39mm cartridge. It is gas operated with rotating bolt lockup. The rifle accomplishes the task of having high hit probability and engagement density by having two barrels in side by side orientation. The two barrels almost simultaneously fire a two-shot burst. I say “almost simultaneously” because the gun is designed to shoot the second barrel with a delay of 0.01 seconds. That short delay ensures that the projectiles don’t affect each other’s ballistics which could happen if they left the muzzles exactly at the same time. The rate of fire of this burst fire mode is 6,000 rpm!

Two muzzles are fixed in the front sight block

The gun feeds from a triple stack box magazine of 45 round capacity. As you can see in the image below, it seems that the magazine is not quite a triple stack one. It is more like a normal two stack magazine welded to a single stack one. You can see the two followers and a dividing wall between the two sections. Even if the cartridge stacks merge together inside the magazine, they are definitely presented separately for feeding.

The AO-63 rifle has a fire control selector on the right side of the receiver. In single shot mode, only one of the barrels feeds from the magazine and fires. Next mode is the burst fire when two barrels shoot together with the mentioned 0.01-second delay. The third full auto mode is very unique. When the selector is switched to full auto and the shooter pulls the trigger, the gun first shoots a two-round burst from two barrels (at 6,000 rpm) then one of the barrels goes on shooting as a normal full auto at a rate of fire of 850 rpm.

AO-63 is like an AK-style rifle with every part of the mechanism doubled: barrels, gas tubes, the trigger mechanism, bolts, gas pistons, gas blocks, recoil springs etc. The bolt carrier is wider to enclose the two bolts, pistons and recoil springs. The dust cover is also wider and has a more squared shape compared to that of AK rifles. That shape of the dust cover is obviously to accommodate the wider BCG. Judging from the cutouts in the dust cover and the location of the plunger ejectors, the gun should eject the spent cases from either side.

You can also see that one of the pistons is shorter than the other one and has a slightly different geometry. As it is seen in the images and considering the way this gun works, the bolt carrier should not be a single-piece part. The two pistons and their corresponding bolts should be free to reciprocate separately.

Judging from the right side location of the two-stack portion of the magazine, I think the primary barrel is the right side one too. If my assumption is true then the primary ejection pattern is to the right side and the primary bolt is the right side one with the longer gas piston. In that case, the secondary (left) barrel feeds from the left side single stack magazine. However, my theory may not be correct, because if it is true then some problems may occur concerning the feeding and magazine capacity. For example, if you shoot the gun in full auto mode in say 6-shot bursts, then after 5 such bursts you’ll have an empty double stack portion and 10 rounds left in the single stack side. Or, if you shoot in the burst fire mode, then you’ll spend the single stack magazine and still have 15 rounds left in the double stack portion.

The trigger mechanism is also doubled

The overall length of the gun is 890 millimeters (35″) and the weight without the magazine is 3.68 kilograms (8 lbs 2oz). The gun also looks to be not too wide (if any wider at all) at the receiver portion compared to the AK-74.

There is also a curious story around this rifle. In a 1989 movie called “Red Scorpion“, Dolph Lundgren’s character uses a double-barreled gun which is supposedly an AO-63. However, it is just a mockup based on an FN FAL rifle.

The one piece dust cover lock with dual recoil spring rear guides and two recoil springs

Although the idea of a double-barreled rifle is more like a utopia, than anything practical, I think this particular rifle is a much better design than the AN-94. By saying “much better” I mean that even though it uses a weird double barrel design, it is still simpler than the AN-94, hence it should be much easier to maintain and manipulate in the field. Particularly, clearing the malfunctions of this rifle should be nothing extremely different than that of the AK-74, unlike the AN-94 which pretty much renders the gun inoperable in the case of common malfunctions like failures to feed or double feeds.

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


  • A.WChuck

    I think it is unneeded and unweldy as an individual soldiers weapon, however it looks useful as a port weapon on an APC or light recon vehicle.

    • RSG

      You couldn’t be more wrong. It is very “weldy”.

      • A.WChuck

        LOL. Me and shpellin don’t get along. Unweildy.

        • GaryOlson

          Don’t you mean inconceivably wieldy despite the weight.
          “i before e except….”

          • A.WChuck

            Crap…cannot get anything right today.

          • phuzz

            More words in English have ‘e’ then ‘i’ than the other way around.

    • iksnilol

      It is light and short, looks like a handy rifle IMO.

  • Anonymoose

    Two AKs are better than one!

    • Major Tom

      Twice as reliable, twice the fire rate and twice the capacity of a single AK too!

  • Malone M. de Araujo

    Gilboa snake AK????? The russians ever think in crazy guns first.

    • Raven

      Nope, the Winchester entry for the SALVO program in 1957 was a double-barrelled T48 FAL. Firing a 5.56mm T65 (7.62×51 case necked to 5.56mm) duplex round, no less.

      • Malone M. de Araujo

        Yeah you is right i forgot the Winchester SALVO
        But a “better” idea is the TKB-059

  • Tym O’Byrne

    Function aside the cool factor is through the roof.

  • DetroitMan

    Cool, but likely prohibitively expensive as a military weapon. Double barreled rifles have to be regulated so that both barrels shoot to the same point of aim. This is a time consuming process involving a lot of manual labor. It’s a large part of the reason that double barreled safari rifles cost as much as they do. The AN-94 might be more complex mechanically, but it is likely cheaper and faster to manufacture than this rifle would be.

  • USMC03Vet

    2 AK > 1 AK

  • Alan

    In Soviet Russia, Grandfather’s old double barrel shoots intermediate cartridge.

    • LCON

      Israel to.

  • BrandonAKsALot

    What’s interesting is the magazine appears to be a joining of the early steel prototype AK-74 magazines. The Russians did the same when they were designing quad-stacks early on. They took two or more slab sides and joined them to produce a quad-stack.

  • Matt

    Wouldn’t the second/delayed round be affected by the recoil of the first round…and go high?

    • Form Factor

      Depends, the Rifle is quite heavy, the 5.45×39 has little recoil, the main recoil actually is from the moving bolt carrier. So the question is if the momentum of the heavy Rifle would be overcome or not, in such a short time of the 6000rpm burst.

      5.45×39 Recoil in the Rifle + 45Rounds in a triplestack = 1.19 lbs sec , 4.06 fps , 2.42 ft lbs

      • iksnilol

        The rifle isn’t really heavy, it’s like 3.7 kg.

    • Darren Hruska

      The second shot would be fired almost certainly before the recoil from the first shot even “peaks.”

  • Андрей Куликов

    This is an experimental rifle. To test the effectiveness of high-temp shooting.

  • Darren Hruska

    Wow, I’ve been waiting years to see actual images of the AO-63! Tkachev was quite the genious, paving the way for the modern PDW and the actions used in the advanced Russian automatic rifle designs we’re more familiar with nowadays (AEK-971, AK-107, and AN-94).

    Actually, Stechkin’s TKB-0146, which is more-or-less like a bullpup AN-94, was the other design that made it to the final Abakan trials.

  • DW

    Why did they not design the gun to simply fire both barrels (with that .001s delay)per firing cycle? If a thing is worth shooting once it’s worth shooting twice right comrades?

  • Jack Holmes

    Nyet, rifle is–oh my god

  • Diver6106

    NUTS… on to the triple, quad… when will it stop? Just use a machine gun, less mechanism and more ammo. The only advantage to a double for combat is if it is a different round; grenade launcher or shotgun.

  • John

    Two is ALWAYS better than one…..except for tumors and alimony payments.