The mechanism of segregation during die filling with a 10–35 mesh lead mixture using a vibrating die is one of filtration of fines down through the moving powder mass. This mechanism is modified by other mechanisms which occur in the powder as a result of the vibratory conditions. The vibration conditions used varied between 0–0.6 inches amplitude and 1–100 c.p.s. frequency. At low amplitude and frequency the powder mass is quiescent. At high amplitude, the powder bounces in the die. At intermediate amplitudes over the frequency range 1–100 c.p.s., a marked churning of the powder mass occurs. During conditions of churning, radial segregation is reduced (i.e., more fines locate in the bottom of the die cavity). Less vertical segregation is observed when churning is absent. The results indicate that in the bottom zone of the die, for conditions of churning, increasing the time of vibration tends to allow some mixing to occur which causes a moderate reduction in the vertical segregation. In the case of the fine (80–325) mesh system, there is an apparent anomaly in the vertical segregation observed, in that the coarse component tends to locate in the bottom zone of the die during vibratory die filling.