Merely guessing here, but they may be SNS casting hardcast 220gr. bullets. I have a number of these but I've never shot any out of the stock bbl and they're not gas checked either. I can't imagine they would lead terribly, but would expect them to lead some.
"There is a principle which is a bar against all information, which is a proof against all argument, and which cannot fail to keep a man in everlasting ignorance – that principle is condemnation before investigation."