Can these be cast with wheel weights and still expand to fit the bore? If not, how can wheel weights be purified? If not possible, how can I scrounge purer lead?

Thanks

I have used the wheel weights that stick on with acceptable results. They are square and have an adhesive on the back. They appear to be almost dead soft and work in a muzzleloader well. Within our family (myself, 2 bro-in-law and 2 nephews) at least ten whitetails have been taken with them. Recovered bullets mushroom like pure lead.