Can a felon own and hunt with a black powder gun?
Pursuant to federal law, a felon cannot own a "firearm" and a black powder would be considered an firearm. But while felons cannot own guns, an "ex-felon" can. An individual can become an ex-felon in one of two ways: having the conviction vacated (overturned) by a court, or obtaining a pardon from either the governor (state offenses) or the president (federal offenses). In either of those circumstances, gun ownership rights can be restored.
In some states a felony conviction can be "expunged"; that is while the conviction is not overturned it is cleared from your record. However, state expungement or "restoration of rights", does not change federal law. Insofar as federal law is concerned, a state expungement or other restoration of rights, is insufficient for purposes of possessing a firearm.