Interesting NYT editorial today "Congress vs the States on guns" which says, in part:

"Yet Congress has refused time and again to help protect Americans from rampant gun violence, and so it has fallen on state lawmakers to address this national crisis. Some state and local governments have banned or restricted certain types of ammunition, or prohibited classes of people, like those convicted of multiple instances of drunken driving, from possessing guns. Others have imposed universal background checks and safe-storage requirements on gun owners."

No wonder there are 20,000 gun laws, as Jim says, or so many and successful challenges to the "inalienable right" of the Second.