The Korobov TKB-022PM experimental assault rifle is a highly unusual and advanced weapon, built by Russian gun designer German Korobov circa 1964. This work was a part of large R&D program, sponsored by Soviet Army and aimed at development of a more effective and less expensive weapon as a possible replacement for the 7,62mm Kalashnikov AKM assault rifle. Working at the TSKIB SOO design bureau in Tula, Korobov first designed the TKB-022P rifle, but it proved to be too awkward and unergonomic. As a result, Korobov then bult an entirely new series of weapons, known as TKB-022PM.
First of these experimental rifles were chambered for the 7,62x39m ammunition, while the last of prototypes, the TKB-022PM5 was chambered for the new 5,6mm ammunition which later evolved into the 5,45x39mm. To make the new gun as short as possible, in his TKB-022PM rifle Korobov used bullpup construction combined with a very unusual action inside. As a result, the magazine was placed very close to the shoulder pad, and the ratio between the barrel length and overall length was very good – with barrel 415 mm long the complete rifle was just 110 mm longer, for a total record length of 525 mm. It was also reportedly more controllable in unsupported automatic fire, and, theoretically, less expensive in mass manufacture than the Kalashnikov AKM, due to the extensive use of plastics. However, the mechanisms of the TKB-022PM were too complicated, and its feed, locking, and ejection system contained too many small and intricate parts to be well suited for mass production and heavy field use.
The TKB-022PM assault rifle is a gas-operated weapon with a gas piston located above the barrel and ejection chute. The gas cylinder is linked to the barrel via a gas block that runs on the left side of the gun, around the ejection chute. To achieve minimum length, it is assembled into bull-pup configuration and uses vertically sliding breechblock (bolt), rather than traditional and most common bolts that cycle back and forth. The breechblock is operated through rocking levers of complicated shape, which interact with dual rollers attached to horizontally sliding action rod. Since the movement of the bolt (breechblock) in this design cannot be used to extract, eject and load cartridges, Korobov developed a special rammer/extractor of very complicated design, which strips the fresh cartridge from the magazine, pushes it forward into the chamber, then, after the discharge, pulls the fired cartridge case back from the chamber. During the rearward stroke of the extractor, the fired case is pushed up in the claws of the rammer/extractor, and on its return stroke spent case is pushed forward too, into the ejection chute that runs above the barrel, inside the action rod which connects the gas piston to the action. The spent cases finally fall out of the gun above the muzzle. The ejection port at the end of the chute is closed by a spring-loaded dust cover. The gun was capable of full- and semi-automatic fire, with a combined safety/fire mode selector switch located above the trigger on the left side of the gun. The gun housing was made from reddish-brown fiber-reinforced plastic, with a metal structure hidden inside. Housing consisted of two clamshell-type halves, lower (with a pistol grip) and upper. Gun was equipped with diopter-type adjustable iron sights. Ammunition was fed from AK/AKM type magazines.
|Full text name||Korobov TKB-022PM experimental assault rifle (USSR)|
|Caliber cartridge||7.62x39mm M43 Soviet Intermediate Cartridge|
|Overall length, mm||525|
|Barrel length, mm||415|
|Weight empty, kg||2.8|
|Magazine capacity, rounds||30|
|Cyclic rate of fire, rounds/min||560|