That’s what I used as well. Tried to round out the caps. About 2 ozs of lead in the biggest one. Then epoxied them to a hardwood dowel. The one inch is kind of deformed now. 3/4 inch one is fine.
I know it’s operator error and not the tool but, I’ll probably buy some. Also made pressure flaker and a notching tool, and a ishi stick. Not having much luck with the indirect stuff but getting a decent flake now and then.