This paper contributes to a modified guidance scheme based on a trajectory tracking method which is dedicated for an artillery rocket with a finite set of single use solid propellant side thrusters. Frequency modulation of pulses was used to achieve effective firing logic. The proposed control law is applicable in the last phase of flight when the rocket reaches the vertex of the trajectory. A correction engine activation sequence was chosen in such a way that possibility of rocket axial unbalance is minimized due to motors firing. Numerical simulation results indicate that significant dispersion reduction was achieved and the number of activated side rocket thrusters is minimized.