The AB-5.45, AB-7.62, AVB-7.62, and LCZ B20 are a series of weapons developed by Russian small arms designer Anatoly F. Baryshev from the 1960s to late 1990s. The mechanism developed by Baryshev allows the latter two of these light weapons to fire full powered rifle ammunition and still be controllable in automatic fire. Due to its firing from an open bolt, they were all unreliable under adverse conditions and inaccurate in single shots which tended to unsuccessfully slam-fire, otherwise the weapon would have apparently worked well. Another variant, the LCZ-B20 was developed in cooperation with Czech company LCZ Group, chambered in 7.62x51mm NATO, but sales were unsuccessful and it was apparently dropped in the late 1990s. However, the LCZ B20 formed the basis of an improved reliable deriv