i foung the weights markings of MC-ZN,contain zink,and will melt at lower temps(600-650 degrees),and will give you fits at the drippers.as stated above watch temp(i have a digital pistol type thermo.put the red dot on what your reading,and its gonna keep you in the heat range needed)and dont allow temp to get over 600-650(pure zink needs 900+degrees. i sort my weights to get out the steel,fe,and mc-zn,and soft strip weights(for black powder bullets),to save headaches,and heat,.i also run the junk weights back to the scrap yard,and they give you wheel weight price.mark