As far as I know he's in favour of gun control - in a kind of American way (no to armour piercing bullets, yes to widespread handgun ownership, that sort of thing). It's not one of the issues for which he is famous.
Ralph Nader is best known for running in the 2000 presidential race. As a Green. He took a lot of votes away from Al Gore and is still widely hated by the left, because if he hadn't run it's likely G W Bush would not have won the election.
You could both have worked that out with less than a minute of Google action.
Not everybody fits the tiny little compartments into which you divide all of political thought.