Comp B explosives are made from TNT, RDX, and wax, such as 59.5 percent RDX, 39.5 percent TNT and 1 percent wax. Desensitizing agents are added. Composition B is used by the military in land mines, rockets and projectiles. Cast Composition B has a specific gravity of 1.65 and a detonation velocity of 'about 25,000 fps and is used as a primer and booster for blasting agents.