After the Second World War various attempts were made to increase the rate of fire of the Berezin machine gun. Reducing the cycle time by increasing the speed of the moving parts was the most obvious thing to do. However, this resulted in a considerable reduction of life and reliability. Another attempt was to reduce the motion length of the moving parts while retaining their speed within permissible limits. N. M. Afanasev took a different approach by introducing an acceleration lever, which transferred the energy of a short motion actuating slide into a long motion of a chambering and case extraction arm. This way the motion length of the actuating slide could remain shorter than the overall length of the cartridge, thus increasing the rate of fire. Later, the same operating mechanism was used in the 23mm AM-23 and ZSU-23 cannon as well.
