Korobov TKB-022 assault rifle [experimental] (USSR / Russia)

7.62mm Korobov TKB-022 experimental assault rifle, first model in the TKB-022 line, circa 1962

7.62mm Korobov TKB-022PM experimental assault rifle, left side, circa 1965

7.62mm Korobov TKB-022PM experimental assault rifle, right side, circa 1965

Caliber: 7.62x39 mm M43 (also experimental 5.6x39mm)
Action: Gas operated, vertically sliding bolt
Overall length: 525 mm / 20.7"
Barrel length: 415 mm / 16.3"
Weigth: 2.8 - 2.4 kg (depending on version) / 6.2 - 5.3 lbs
Rate of fire: 560 rounds pr minute
Magazine capacity: 30 rounds

The line of TKB-022 experimental assault rifles is one of most intrigying developments in small arms, made in Soviet Union. In many respects these weapons, designed during early sixties by Soviet gun designer G. A. Korobov were many years ahead of its time. Those guns were simply too advanced for conservative-thinking Soviet Army officers who preferred simple, familiar, proven and reliable Kalashnikov assault rifles over anything else. Regardless of thst, the TKB-022 is well worth mentioning, if just for the sake of curiosity.
TKB stands for Tulskoe Kosntructorskoe Buro - Tula Design Bureau, an arms-designing organisation associated with Tula arms factory (TOZ), which later evolved into the KBP - large and famous arms design and manufacturing state-owned company. Korobov was one of the more advanced designers at KBP, and he always tried to step ahead of its time. In this case, he tried to create a compact weapon, suitable for motorized troops riding in cramped armored personnel carriers (BMP, BTR) or helicopters. Despite very compact size, this weapon retained full-length barrel (and thus effective range and lethality) of much longer standard assault rifles such as Kalashnikov AKM. In fact, TKB-022 has best barrel length to overall length ratio among most military rifles ever built. During mid- to late sixties Korovov produced several variations of the TKB-022, from TKB-022PM to TKB-022PM5. The last one, the TKB-022PM5, which was produced in 1968, was chambered for then-experimental 5.6x39 ammunition (which latter evolved into 5.45x39). All weapons were tested by Soviet army, but turned down on unpublished reasons (most probably becuse the gun was simple too advanced for contemporary military thinking, but also possibly because no-one at the time could tell for sure if plastic housing would hold its integrity in extreme weather conditions or during many years of storage or use).

The TKB-022 assault rifle is gas-operated weapon with annular gas piston located around the barrel. To achieve minimum length, it is assembled into bull-pup configuration and uses vertically sliding bereech block (bolt), rather than traditional and most common bolt that cycles back and forth. Since the movement of the bolt (breechblock) in this design cannot be used to extract, eject and load cartridges, Korobov developed a special U-shaped rammer / extractor, that strips the frech cartridge from magazine, pushes it into the chamber, then, after the discharge, pulls the fired cartridge case back from the chamber. Upon feeding the next fresh cartridge, the fired case is pushed forward and slightly up, into the ejection chute above the barrel. Spent cases finally fell off the gun above the muzzle. Gun was capable of full- and semi-automatic fire, with 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 plastic, with metall structure hidden inside.