The influence of lead nitrate, red lead, lead chromate, lead floride and lead carbonate on the combustion behaviour of double base propellants in the pressure range-35-140kg/cm /sup 2/ was studied. While all these compounds increased burning rates in lower pressure range (35-60 kg/cm/sup 2/) and higher pressure range (120-140 kg/cm/sup 2/), only lead chromate and lead fluoride were effective in the intermediate pressure range of 60-105 kg/cm/sup 2/. None of these compounds were effective as platonizer, except lead fluoride, which lowered n value to 0.34 in the lower pressure range. Addition of carbon black along with lead compounds raised burning rates further and reduced n values significantly in the higher pressure regins. A probable mech...