True. But banning the metal pipe called "a gun" yet allowing the free sale of ammunition is akin to banning the wooden pipe called "a bong" yet allowing the free sale of tobacco, marijuana, hash-hish, and opium.
The metal pipe is just that - a pipe. In and of itself it doesn't pose a threat to anybody. I suppose you could use it to conk someone over the head, but a baseball bat would be at least as good for that purpose.
Hey - let's ban baseball bats!