The furnace is not a problem.
I'm not concerned with the lead toxicity....I've eaten my share of shot pellets
I'm just toying with the idea because I have access to an almost unlimited supply of brass and copper as well as some lead from time to time.
The molds I have are steel.
The non expanding aspect is not an issue either, I prefer hard cast lead for hunting, I don't want expansion, I want penetration.