I disagree.
Thompson and Huckabee have better records on RKBA.
Keep in mind Ron Paul's notorious vote against the PLCAA and his endless pork-barrell earmark requests and it's easy to see why conservative gun owner's roundly rejected him.
I don't know about better records. Ron Paul is a pretty strict constitutionalist. You could say to a fault. I've never read anything on him that was anti gun rights even with respect to assault weapons. As for his vote against the PLCAA, I believe that has to do with his not wanting over reaching federal regulations but rather those matters left up to the states. I know that's always been his position. The Pork Barrel earmarks you talk about was nonsense in my opinion. He's by far the least wasteful congressman by far. I seem to recall reading he asked for things his constituents wanted , because they asked him to , then voted against most all of them. He's by far the most fiscally responsible of the bunch.