Interesting Georgia case
Pdf here. The gun owner was convicted of a drug offense in 1969, and received a full pardon in 1995. When he tried to purchase a firearm, the NICS staff called a local judge and asked him to revoke the fellow's pistol permit (which I suspect is a BIG violation of the Privacy Act). Basis was a Georgia statute that says persons convicted of a drug offense are forever ineligible to get a pistol permit.
Initially he surrendered his permit, then got new counsel, John Monroe and Douglas King, and they put up a fight. The judge ultimately rules for them. A pardon is an executive act, authorized by the state Constitution. The Legislature cannot change its effect.
He then sued for an injunction against Federal authorities stopping his purchase and seeking an injunction against them prosecuting him. Here's the GeorgiaPacking.org webpage on the pleadings. Word is that the government caved in, and provided him with a certification that he is not prohibited to purchase and possess.
Hat tip to reader Ed Stone...