Have you thought about the 1968 GCA regs?
various firearms that don't qualify as firearms per that law for Feds:
blackpowder.
antiques from 1898 or earlier that shoot blackpowder shells made precisely for that caliber.
the ATF...being the turds they are...have tried to bust folks who have done their time for using universal smokeless in antique firearms.
there is an outfit called Obsolete Ammo that can make any black powder antique cartridge one can think of...just about.
But....local laws will apply to a fed felon....so I would check those too. Most states except the hardcore blue ones mimic the Fed statutes on blackpowder and felons and a number of southern states grant firearms rights back to felons after satisfactory parole.
the 1968 GCA was instituted to provide review and relief for felons to get their gun rights back upon completion of sentence and/or paper and applying to the ATF....that was nice of them since that is when we first started yanking gun rights pell mell (except Reconstruction)...somehow we survived 200 years with ex-felons with guns...the horror..lol
A Republican Congress yanked funding over 10 years ago so it's a catch 22....the ATF cannot do the job it was legislated to do. Two years ago, SCOTUS ruled that local Fed judges could not grant waivers as they once could.
As you know....the min-man is a 5 spot unless you get really really lucky so it's a minefield and some AUSA chingao will love to climb his career over some shmucks back.
Regards
PS....about one in seven adult males has now lost gun rights for some infraction...all of which are not felonies anymore. I doubt any pol will pick up this sword do you? Why outlaw guns....it's easier to outlaw gun owners.
Speed, have you tried to get that felony expunged?