I am sure this question has been asked before, but I can’t find the answer.

How do I turn roofing lead into lead suitable for casting 357’s, ie hard cast.

I have quite a bit of old roofing lead, in fact, loads of the stuff, all collected over the years from various jobs. I have been going through it and melting it all down in an old saucepan and casting into a Lee ingot pan to get rid of the crud. So now I got loads of clean ingots, which from what I understand is pure lead.

So what do I need to add and how much to harden it up so I can cast for my 357?

Ideally I want something I can just go out and buy, not spend ages hunting about for other scrap.

All help and pointers much appreciated.

Thanks

Dave