Bruce,

The point is that such a ban would have no real effect.

Fully automatic weapons are already effectively banned.

I can fire 11 rounds from my (target) revolver faster than I can fire 7 rounds from a 1911 Colt semi.

The crimes that everyone is commenting on WERE IN VIOLATION OF THE EXISTING LAWS.

Why does anyone think more laws will make a difference?

ANYONE can make a single-shot gun, and use it to obtain a weapon ( from a leaga source, such as a policeman, or a retired policeman) With more than 320 million known guns in the US, how effective would a ban be? Who would turn in the guns - the criminals who are already in violation of the law for possessing them?