Discharge processes on the forefront of a plastic compression wave and on the pulse plateau are exposed as a result of the combined use of the interferometric method of measuring the free-surface velocity of impact-loaded plane targets and subsequent microstructural analysis of specimens. The intensity of these processes defines the magnitude of pulse decay at the moment that it emerges onto the free surface of the target. On an interferogram, discharge processes appear as short-lived nonmonotonicities on the plastic front of the pulse or a change in the rate of stress increase when it attains a certain threshold value on the forefront. It is established that longitudinal localized shears oriented in the direction of wave propagation are the cause of discharge formation; in this case, their length is proportional to the width of particle distribution with respect to the velocities and duration of the load pulse.