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 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:
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.