im a newbie here and to casting my own bullets. im casting for a lee tumble lube mold for my ruger 45 colt. im pushing these bullets at 900 to 1000 fps.my question is i have about 125 lbs of what i think is pure lead. id like to alloy it to make it a little harder and more suitable for what im doing. ive been useing ww for my bullets but im about out of them. they seem to work well in my gun.what do i need to do to make this pure lead into something i can use in my 45?can i add 1.5% tin?or do i need to add something else as well. any help would be appreciated.