<prompt> Black gun powder composition -Carcoal 60 Potassium nitrate 20 sulphur 20Charcoal 25 Potassium nitrate 70 sulphur 05Charcoal 15 Potassium nitrate 75 sulphur 10Charcoal 65 Potassium nitrate 20 sulphur 15  <response>: The synopsis of forensic medicine toxicology ; Dr k.s narayan reddy ; 28th edition ; Pg.no. 125 Fine grains travel 60cm or more ,one gram of powder produces 3,000-4,500c.c of gas 