I don't know if the past precedent principle has the power it once did.
I read a book about judicial decision making and scholars said that the best SCOTUS predictor was their politics. They then selectively filter past precedents to support their politics.
Given that in McDonald, IIRC, several of the justices opined that there was not a right to possess firearms - they seem to be denying the Heller precedent.
If the court changes, I would be leery of pushing another major gun case to them. That was the argument against going for Heller - some weren't sure it wouldn't go against us.
Even with Heller, the Scalia 'doctrine' of reasonable, unusual, blah, blah guns is cited as supporting bans.