I wouldn't ask a question about brain surgery on a forum populated by Mensa members, even if a few of them were GP's. And I wouldn't ask a legal question on an S&W forum, even if a few members were lawyers licensed to practice in and familiar with the laws of their own states.
Federal carry permit?
If you want a good practical answer to this question, get in touch with Massad Ayoob and see about taking LFI-1, if it is still around. Once you have assimilated what Mas has been teaching, you will be ready to consult a lawyer in your state, and maybe even divine whether or not he is competent to advise you legally. Until then, do not confuse yourself with a policeman, and recognize that you don't always know what's going on, even when you think you do. With certain exceptions that vary from state to state, you'd best regard that gun as a last-ditch safety device that has no purpose other than to keep YOU or YOUR family alive.