Measurement of a muzzle missile velocity usually represent Doppler radars. The rating of a muzzle velocity is shaped on the basis of measurement of a missile velocity on various sections of its trajectory. Thus from the point of view of design of a meter and the exact choice of its parameters the rating of a radar maximum operation range has an essential value. The range of action determines an amount of cycles of measurement which can be implemented for one shot so, essentially influences magnitude of an aggregate error of muzzle velocity estimation. In the given type of meters on a maximum operation range except for classical radar factors: transmitted powers, performances of antennas, noise nesses of the receiver, etc., essential effect render geometrical factors, the bound with a mechanical trajectory of shell, and factors, the bound with a breadth of the shell backscattering diagram. As shown in the given paper, the joint registration of all these factors results in appearance of essential limitations on a maximum operation range which are necessary for taking into account at system design of a meter.