The gas engine of the gun ensures reliable functioning of automatic equipment when using cartridges with any mass of fraction and gunpowder. Besides its design interferes with pollution of mechanisms of the weapon products of combustion of a powder charge and promotes reduction of energy of return. The new system of sealing of the POWER DRIVE gas outlet detains the maximum volume of powder gases when firing by ammunition with a small hinge plate of gunpowder, and length of the course of the gas piston is increased on 20.
The design of the shock and trigger mechanism of the gun provides faster operation. In comparison with other models of autoloading guns the reaction time of USM is reduced by 24%. Nature of descent is improved, reliability of its functioning is considerably increased.