Reloading shotgun slugs

I have a deerslayerll that has been in the cabinet for years. All of my deer hunting is done with black powder. Anyway

I want get out the ole deer slayer and use it but the slugs are so expensive it's prohibitive. The "shotgun" has a rifled barrel. Is it practical to reload slugs for this gun? I have been lookin around a bit and see that Lee makes a slug mold where the slug can be loaded in a AA hull. I have a Lee shotgun press that I have used for shot for years. Anyway can someone help me with this problem?

thanks for the help