Of course, the Consitution is not a vaccum, it is a living thing created and modified by many different human hands. The right to own slaves was also once in the Constitution, so was the barring of the alcohol trade. Also, it doesn't say you have the right ot own a gun, it says you have the right to 'bear arms'. So, constitutionally speaking, you could buy a nuclear warhead and prop it up in your backyard and say, "I'm just exercizing my right to bear arms". That doesn't mean the gov't won't come and take it away from you. And as well they should.