Audio and Text of DC v Heller Is Here, The Right to Keep and Bear Arms -- Check It Out

And take a listen to the questions of Chief Justice John Roberts to DC atty Walter Dillenger, who is a real tool.

http://www.oyez.org/cases/2000-2009/2007/2007_07_290/argument/

Then, just read the Constitution for yourself and don't bother asking what government folks "interpret the Constitution".

Then buy a gun, or many.