I think if someone committed a non-violent felony and served their time. They should be able to possess a gun. Violent ex felons, maybe not. There are a lot of things a person could be convicted of being a felon. Theft without a weapon. White collar crime like embezlement, drug use, accidental manslaughter from say a DUI. Breaking and entering without a weapon. I think after they did their time, their probationary time, and stayed clean for a while, then their complete civil rights should be restored. Felons shouldn't be allowed to vote until they did their time, etc.
I know a friend who had a restraint against him in a previous divorce about 10 years prior. Kept him from being able to own a gun. He went back to Missouri and got the governor to pardon him, and got his gun rights back. Took a lawyer, about $2,000 and a job with the county engineering department to get cleared. Never convicted of anything, just a restraint order by his by-polar ex wife.