I believe some of the guys didn't quite get that you wanted "legal" advice and not medical advice. To my knowledge there aren't any lawyers or physicians on this site, but I'll take a stab. I don't believe that a Bi-polar diagnosis (or any other physical/medical condition for that matter) would be part of your record, or, in itself, prevent you from buying a gun or hunting. Any behavior that may have resulted from your condition that would be on a police record, etc. might present a problem. If you are on meds, just keep taking them and you should be alright. Have fun and be safe.