I can’t answer your question at all, as I don’t cast any boolits. But I would like to thank you, because of your post I refamiliarized myself with the John/Lorena Bobbitt story and learned that John made an adult movie titled “FrankenPenis”. And that gave me a jolly or two.
(The title of the movie gave jollies, not the movie itself)
Too many variables. Babbit is broken down into 2 main categories, believe it’s tin and lead free (iirc) good additive to lead to cast bullets though. That’s all I know about it: I say grab it and figure it out.
I would think high tin babbit would be a little brittle for bullets, but it might be useful for alloying as has been said. Only time I have ever had to deal with it was turbine bearing pedestals.