AKB and AKB-1 – Soviet Trial Balanced Action Rifles

The Kalashnikov Museum and Exhibition Complex of Small Arms has released another video showcasing a pair of rare trial rifles. These are balanced action rifles which took part in “Abakan” trials and were AN-94 rifle’s competitors. The guns are called AKB (АКБ) and AKB-1 (АКБ-1) and both are designed by a group of designers lead by Victor Kalashnikov (Mikhail Kalashnikov’s son). Below is the mentioned video. Although it is in Russian, you’ll find the explanation of the content below the video:

If you remember, in balanced action firearms the moving parts consist of two elements – the bolt carrier group that moves rearward and another part of equal mass as the BCG but moving on opposite direction (forward). This layout allows to balance the momentum of the moving parts and eliminate its effect on the recoil impulse thus decreasing the felt recoil. At least in some designs, the two moving parts also hit each other (somewhere near the center of gravity of the gun). That design feature prevents the moving parts from hitting the receiver (rear trunnion) of the firearm. That also helps to significantly mitigate the felt recoil. Now let’s see what unique features the two guns have.

AKB

AKB rifle was the first of these two. It was designed in 1984. It uses the barrel as the forward moving balancing part! The movement of recoiling BCG forces the barrel to move forward via a gear mechanism. The rifle is capable of firing in semi auto, full auto (1100 rpm) and three shot bursts at 2000 rpm. Note that the barrel is moving inside the barrel shroud as in many designs with moving barrels. Here is how AKB rifle’s BCG and barrel work:

AKB-1

This version was developed a couple of years later – in 1986. It also has same fire control settings and rates of fire as the AKB, except in the burst mode this rifle shoots 2 round bursts. The difference is that this one has a fixed barrel and a separate forward moving part sort of protruding from the gas block as seen in the animated image below. This solution is also more reminiscent of better-known AEK-971 (A-545) rifle.

Both rifles are chambered in 5.45x39mm and feed from standard AK-74 magazines. Although both AKB and AKB-1 proved to offer an improvement in hit probability from unstable positions (e.g. standing) compared to the AK-74, they lost the trials. As you know, the result of Abakan trials was the adoption of the AN-94 rifle.

Many thanks to Efim Zagrebin (Kalashnikov Museum employee and the host of the video) for assisting in writing this article.





Hrachya H

I was born and currently live in Armenia, where I work in a family business of leather goods manufacturing. Being a retired sergeant of my country’s armed forces and a lifelong firearms enthusiast, I always enjoy studying firearms design, technology and history. Also my knowledge of Russian allows me to translate and make Russian/Soviet/Combloc small arms related information available for the English speaking audience.
Should you need to contact me, feel free to shoot me a message at TFBHrachyaH@gmail.com


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  • Suppressed

    How does the AKB almost double the RPM in burst mode vs full-auto, or is that just a typo? (Genuine question here, not ballbusting)

    • SGT Fish

      maybe 2 moving parts are twice as fast as one moving part? each component has to move half as far. so cutting the action cycle time in half?
      that’s my assumption just by looking at the clip

    • Younggun

      Perhaps someone with more knowledge on the function of these specific designs can give a better answer but the AN-94 also had a higher rate of fire in burst mode as opposed to single or full auto due to an auxilary “loading dock” if you will. A second cartridge was not loaded directly into the chamber from the magazine but rather went to a separate compartment for 2 round burst because the magazine could not feed fast enough to keep up with the rate of fire. Perhaps these rifles utilized similar designs.

    • Hrachya H

      Not a typo, that’s what it says in the video. Unfortunately I can’t find any source explaining how that different rate of fire mechanism works in these guns.

    • Collimatrix

      A number of the rifles that trialed against the AN-94 had both a rate of fire limiter and a burst limiter. In regular full-auto the rate of fire limiter was engaged, in burst fire only the burst limiter was engaged.

    • cowboybob

      If it’s anything like the AN94 it has a separate little feed shelf where every other round is stored, and the bolt can cycle twice while the barrel recoils a single stroke. So it’s not picking up a round from the magazine on the second stroke, it’s picking the round up from the little feed shelf. Which makes the bolt stroke shorter and and increases the rate of fire.

      I don’t know exactly how it works on the AKB, but it’s a clockwork nightmare on the AN94.

    • Voice from East

      Basically, rate of fire depends on how fast you moving parts are circle(depends on mass of parts and amount of pressure applied) and how far they’re rolling. The traditional AK pattern have a really big overtravel path(somethere 4-5 “bonus” cm), cut it, lighten moving parts and apply more pressure on gas system and you’ll get that’s you need.

  • Jared Vynn

    Wouldn’t such a design increase the weight of the rifle completed to a more traditional design?

    • DIR911911 .

      even 1 pound for no recoil would seem like a bargain

      • FF

        “No recoil” … you only prevent bolt carrier recoil, but not projectile&propellant recoil.

        • Houston Moore

          Muzzle brake, though.

          • roguetechie

            Yes, and braked 5.45 isn’t the ear destroying buddy slapping ISIS terrorist Abu hajar like 5.56 is!

            Loaded rounds are about 2 grams lighter and the bullets have a noticeably higher length to diameter ratio, yet somehow pretty much play in the same or better velocity sandbox as 5.56 from a 16 inch barrel.

            Speaking as someone who admires success over country of origin, I gravitate towards 5.45 now that health issues keep me from being able to pull run n guns with a 20 inch HBAR!

            Why would some jackass run n gun with a short stocked 20 inch HBAR?

            WEEEELLL… You see, I’d like to think I’m a pretty decent shooter but I miss with the first shot enough that I was obliged to learn to just always fast double tap stuff LOL!

        • Flounder

          What if… The weight going forward was just a few ounces more to counter it!

          If you add the whole stinkin system… There isn’t a limit on what exactly you can counteract. And just getting rid of the carrier recoil could improve how much fun a gun is to shoot a tremendous amount.

    • Paul Epstein

      It doesn’t look like it would be that significant, with the AKB the only real additional part is the barrel shroud, the forward moving components would already be present on the AK74, they’d just be fixed in place. The AKB1 might be heavier, but that depends on how the telescoping part works, it’s replacing a solid piece of steel so it might genuinely be lighter.

      With a balanced action, you’d want to decrease the weight of the normal rearward moving parts like the bolt carrier and piston in order to minimize the weight and complexity of the countering part. Because of the gear system, both moving assemblies add to the force extracting and chambering a round, so you just need them to have a combined mass close to the normal bolt carrier.

      • Hrachya H

        I think Paul is correct.

  • Paul

    Wow, FPS Russia’s fake accent has really improved.

  • Patriot Gunner

    Hrach, bravo aper! Great article! It still amazes me that these guns were produced in the 80’s as well as the wonders from the western world like the G11. Ahh, its nice to think of a world where these weapons are standard infantry issued rifles. Oh what could have been.

    • Hrachya H

      Thanks, brother! 🙂

  • Anonymoose
    • mechamaster

      They succeeded by the superior and expensive 94 members idol group, labeled AN94.

      LoL.

  • Rnasser Rnasser

    You can shoot a 5.56 with no brake pretty fast and accurate…. the added complexity is not worth it.