I actually realized you are correct in regards to the 2nd amendment, since there are 3 distinct groups recognized in the constitution, the feds, the states, and the people. It clearly says "the right of the people ..." and "... shall not be infringed" meaning states, or local government do not have the power to restrict that right in any way.
However, I firmly believe in "states rights" in the respect that they may pass laws that the federal government would not be allowed to, such as a law respecting an establishment of religion, the constitution very clearly says that power is prohibited to congress, as an example.
Also, you referred to firearms in the 2nd amendment, it says "arms", which means any weapon. The founders fought the revolutionary war with privately owned warships, artillery, and other such weapons which where the most powerful of the time, so I think they fully intended those that could afford things such as tanks, AFVs, naval warships and submarines, and tactical and strategic aircraft, have a right to possess them. "Arms" also encompasses weapons we can not conceive of yet, like something out of science fiction.