TKB-022

1), developed at TsKIB SOO by the small arms designer German A. Korobov in the 1960s. The weapons were gas-operated with an annular gas piston located around the barrel and a vertically moving bolt, which made it possible to minimize the length of the receiver group. A U-shaped rammer/extractor was used to chamber and extract the cartridge by pushing it into the chamber where after discharge was pulled back from the chamber and again, upon feeding the new cartridge, pushed forward and slightly up into an ejection tube running above the barrel, from which it would finally exit above the muzzle. This ejection mechanism made it possible to fire the weapon both right- and left-handed. These weapons had the best barrel length to overall length ratio among the assault rifles. Firing from an unstable position, the TKB-022PM No. 1 and the TKB-022PM No. 2 had three times better accuracy than the AKM. The TKB-022PM5 No. 1 had better accuracy than the AKM when fired from a hand in a lying position at a distance of 100 meters. Although these assault rifles performed well, they were turned down by the Soviet Army for being too radical at that time. Additionally, there were concerns about the displaced center of gravity to the tail end of the weapon and the durability of the weapon's plastic housing during prolonged operations under difficult conditions or during storage.

• Name — TKB-022PM • Origin — Soviet Union • Type — Bullpup assault rifle • Is Ranged — YES • Designer — German A. Korobov • Design Date — 1955 • Manufacturer — TsKIB SOO • Length — 525 mm • Part Length — 415 mm • Rate — 560 rounds/min • Feed — 30-round detachable magazine • Sights — Adjustable iron sights • Illustration — A photo of the TKB-022PM above the TKB-022P

The TKB-022 series of rifles were developed at TsKIB SOO by German A. Korobov as part of a research and development program backed by the Soviet Army for a potential new rifle that could replace the newly adopted AKM (adopted in 1959), as a better and cheaper weapon. In 1962, Korobov created the TKB-022P rifle, which was chambered for 7.62x39mm and built primarily with a fibre-reinforced polymer known as AG-4, a new material at the time. However, this rifle was rejected due to the large and curved AKM magazine functioning poorly as the weapon's pistol grip. Using the experience gained from his prior development of his previous bullpup, the TKB-408, Korobov next sought to design a new bullpup rifle with as little length and weight as possible, resulting in the TKB-022PM and its revisions. Prototypes were submitted, however they were all rejected by the Soviet military for multiple reasons. The primary issue was the complexity of the weapons' internals, which involved many small parts that were deemed unsuitable for mass production and extensive field use. Malfunctions that occurred during firing usually required total disassembly of the weapon. The physical appearances of these rifles were considered "an eyesore".

The TKB-022PM rifles were gas-operated, select-fire assault rifles with single-action triggers. The gas piston is placed above both the barrel and ejection tube, with the gas cylinder connected to the barrel using a gas block to the left of the mechanism. A switch on the left side of the gun allows the user to select been safe, semi and fully automatic fire, and the iron sights are adjustable. The weapon's bolt also functions as a breechblock, to help achieve a shorter length. Rather than moving in the common horizontal motion of traditional bolts, it moves vertically instead. An action rod, which slides horizontally, has attached to it a set of dual rollers, which move rocking levers that operate the bolt. Due to its vertical movement rendering it unable to extract, eject and load cartridges, a unique and complicated rammer and extractor was designed. As the extractor moves backward, the spent casing is elevated upwards within the extractor, then moved into the ejection chute once it advances forward, eventually to be ejected out the front of the gun. A spring-loaded hatch covers this chute's opening. This ejection method allowed the firearm to be used ambidextrously, as well as reduce the effect of discharged gases on the shooter's mucous membrane. Much like its predecessor, the TKB-022P, the weapons' housings were primarily created from fibre-reinforced polymer, manufactured as upper and lower halves rather than the TKB-022P's left and right halves. With an empty magazine, the entire weapon weighed 2.8 kilograms. In theory, the use of plastic would have also provided a lower manufacturing cost than the AKM, which costed around 42 Russian rubles per rifle in the 1960's. The TKB-022PM was chambered for 7.62x39mm cartridges, and was designed to use AKM magazines situated as close to the back of the gun as possible, which would allow for the barrel to maintain a good length while keeping the firearm compact. This design resulted in a length of 525mm, with 415mm containing the barrel. The TKB-022PM5 was the final prototype, being chambered for the 5.6x39mm round, which was new at the time.