About a year ago, back in 2018, the Russian Ministry of Defense officially announced results of the “Ratnik” trials in regard to new assault rifles. It recommended for adoption not one, but four rifles in two calibers. Those included 5.45x39mm AK-12 and 7.62x39mm AK-15 rifles from the Kalashnikov Group and 5.45x39mm A-545 and 7.62x39mm A-762 rifles from the Degtyarov Plant, also known as ZiD.
The two Kalashnikov rifles represent the latest iteration of the classic design, originally adopted by the Soviet Army some 70 years ago. These rifles were recommended as potential replacements for an existing bunch of AK-type rifles in general service in the Russian military, including the 5.45mm AK-74M and older 7.62mm AKM rifles. As of early 2019, the Kalashnikov Group confirmed governmental orders for at least 150,000 of the new 5.45mm AK-12 and 7.62mm AK-15 rifles, plus an unspecified number of export orders.
Rifles from Degtyarov were recommended for adoption by Russian Special Forces, and so far no specifics are available for the possible number of rifles on order, but it is safe to assume that numbers would be much smaller than those mentioned above. However, both ZiD rifles, which differ only with cartridges they use, are sufficiently unusual in design to warrant this article.
Unusual ZiD Rifles
The most unusual and unique aspect of the A-545 and A-762 rifles is their so-called “balanced action.” Originally devised in the mid-1960s by Soviet small arms engineer Pyotr Tkachev, this system adds an additional gas piston and operating rod to otherwise more or less traditional gas-operated action. It is a common fact that the unrivalled reliability of AK-type rifles comes from, among other things, heavy bolt groups reciprocating inside receiver with significant velocity. Under normal circumstances, an AK-74 bolt group, which weighs around 500g, slams against the rear trunnion inside the receiver with terminal velocity of 3m to 4m per second. This creates significant additional recoil impulse that disrupts aiming and increases muzzle rise during full-automatic fire. An additional impulse is created when the same bolt group slams the front trunnion after chambering the next round. The simplest way to reduce shocks and vibration from these impulses is to adopt a “constant” or “soft” recoil system, similar to that used in the Utimax machine gun, where the bolt group does not hit the receiver upon its travel back. However, this simple system results in a longer receiver and decreased reliability under harsh conditions.
Tkachev’s idea was to counter and neutralize these impulses with addition of the counter-mass, moving inside the gun in a direction opposite to movement of the bolt group while having the same velocity and, if possible, mass. That way a shooter won’t experience additional recoil shocks from movement of the bolt group, and full-auto or rapid semiautomatic fire dispersion would be noticeably decreased without sacrificing power necessary to overcome dirt, powder residue or frozen grease during extensive combat.
History of Balanced-Action Assault Rifles
Starting in the late 1960s, balanced-action assault rifles were designed in parallel at two leading small arms development centers: in Izhevsk, it’s IZHMASH, and in Kovrov, it’s KMZ, Kovrov Mechanical Plant. IZHMASH produced a line of rifles designed by Mikhail Alexandrov, which started with the AL-5 and culminated in the unsuccessful AK-107. Early work in Kovrov resulted in the 5.45mm Konstantinov SA-006 assault rifle, which competed against Kalashnikov AK-74 and eventually lost trials in 1972 to 1973, as being more complicated, more expensive and having some other issues, while offering only limited improvements over the conventional 5.45mm AK and only when firing short bursts from off-hand positions.
Despite this setback, designers from Kovrov continued their work on balanced-action rifles, which resulted in the AEK-971, a 5.45mm balanced-action weapon which was extensively tested during the “Abakan” trials of the late 1980s and early 1990s and lost it again, this time to Nikonov AN-94, another unusual rifle that features an entirely different system. Undeterred, KMZ continued development of the AEK-971 until around 2006, when it passed all small arms development to another factory located in the same city, the aforementioned Degtyarov Plant, or ZiD in short. During the late 1990s and early 2000s, KMZ produced small batches of AEK-971 rifles for use by Russian police SWAT-type units, but the military remained mostly uninterested in this gun.
However, around 2012 the Russian Army initiated the R&D program that sought new and improved assault rifles, with better effectiveness, improved ergonomics and modern sight interfaces. For these trials, known as “Ratnik” (medieval Russian warrior), ZiD submitted severely modified balanced-action rifles, heavily based on the earlier AEK-971 but with redesigned receiver and stock. As said above, those rifles eventually were recommended for adoption by Russian Special Forces, and the final goal of our article is to describe these interesting rifles for western readers. In the course of tests, the A-545 rifle received an official GRAU index of 6P67, and A-762 was designated as 6P68.
It must be noted that while all descriptions below refer primarily to the current A-545 rifle, they’re also applicable to the A-762 as well, which differs only by caliber and type of ammunition used. Differences from earlier the AEK-971 rifles also are mentioned in the text, where applicable.
Assault Rifle Comparison
The A-545 assault rifle has a gas-operated, balanced action with rotating bolt locking. “Balancing” means that the gas system has two co-axial gas pistons. The primary gas piston has annual shape and is linked via the tubular operating rod to the bolt carrier and operates as usual. The second gas piston is linked to a balancing steel weight and moves in the opposite direction to the main gas piston, inside its hollow tubular body. As a result of this setup, the gas tube has a “T” shape, with the gas port located in the middle. Both pistons are synchronized through a simple gear (in early models) or two gears (in current production models). Gears are assembled into a small caret which remains stationary inside the action when the gun is fired, as it forms an integral front part of the return spring guide rod. The synchronous and opposite movement of the balancing weight eliminates all impulses except one generated by projectile and burning powder, so the rifle becomes more stable during full-auto fire and vibrates less.
Production AEK-971 rifles had side-folding plastic buttstocks, plastic forearms and fire control grips, and used standard AK/AKM or AK-74 30-round magazines (depending on the chambering). They also featured safety switch/fire mode selectors of various designs, depending on the year of manufacture and factory. The fire selector normally permitted three modes of fire: single shots, 3-round bursts and full-auto. Inner workings of the gun were accessible through a detachable top cover, made from stamped steel.
The A-545 rifle features numerous internal and external improvements over earlier AEK-971s. These include, among other things, a redesigned receiver with integrated Picatinny rail on the top and hinged pistol grip/trigger unit at the bottom. This rifle is disassembled by removing the rear end-cap from the receiver, swinging the pistol grip down and then pulling out the bolt group with recoil spring and synchronizing gear cart as a single unit. Other features include ambidextrous fire mode selector/safety levers (with positions for safe, single shots, 2-round bursts and full-auto), retractable and adjustable shoulder stock and aperture rear sight. It is interesting to note that early A-545 and A-762 rifles featured HK-style drum rear sights, while later models replaced them with more common types of tangent rear sights.
To achieve the desired weight, a set value under the “Ratnik” program requirements, the A-545 features several parts and subassemblies made from titanium alloys. It also features a diopter-type rear sight; although iron sights are seen now mostly as back-ups for red dot or electronic night sights. The barrel features a quick-removable muzzle brake/compensator which can be replaced with a tactical sound suppressor, optimized for work with standard issue, supersonic ammunition.
According to published information, the A-545 indeed offers less dispersion when firing 2-round bursts, compared to the AK-74M or AK-12. The same is applicable to the A-762 compared to the AKM or AK-15. However, in single shots, conventional Kalashnikov-type rifles proved to be more accurate; although there’s no explanation why. Overall, the Russian press quoted that the A-545 offered 10% more combat effectiveness compared to the AK-12 when used at ranges under 300m. At extended ranges, the AK-12 has a slight edge over the A-545, which is also close to 10%. When seen from outside, the A-545 appears to be more “modern,” with its plastic lower receiver, solid top with integral Picatinny rail and ambidextrous controls.
However, some of its features raise questions when the gun is actually handled. Its “HK-style” retractable stock with relatively small butt-pad, which has to be rotated 180 degrees between a retracted (combat) and fully collapsed (storage) position, is less than ideal and does not offer a good cheek-weld. Its balanced action requires more force to manually cycle the bolt, is noticeably more complicated and requires more meticulous and time-consuming maintenance when compared to AK-type rifles. Other less obvious but inherent set-backs of the balanced system are increased cyclic rate of fire, about 900 to1000 rounds per minute, and a slight loss of the muzzle velocity due to more powder gases used up to cycle dual pistons.
Conclusion
Unlike conventional designs, it is almost impossible to produce short-barreled PDW or CQB-style rifles with balanced action without significant redesign. The final, and probably most important, problem with the A-545 is its cost. It is believed that the initial unit price, quoted by the factory to the Russian Ministry of Defense, is about three to five times higher than the unit price of the new AK-12 in the same caliber. Considering that the A-545 offers only a stated 10% increase of combat effectiveness over 200% to 400% increase in price, it is not hard to see why the A-545 and A-762 were recommended only for relatively small Russian Special Forces.
Caliber: 5.45×39 (A-545) or 7.62×39 (A-762)
Overall length: 960mm
Length with the stock collapsed: 720mm
Barrel length: 420mm
Weight, with empty magazine: 3.5kg
Magazine capacity: 30 rounds
Rate of fire: 900 to 1000 rounds per minute
