Why not? I've heard of dozens of cases where lawmakers clamor around about making a new law to do X and then find out there were already cases of that law on the books that were ignored.
Banning guns is as intelligent as moving a Deer X-ing sign because you want the deer to cross elsewhere. All you will do is take those who obey the law and strip them of a right. Those who already break laws and disregard them will show just as much disdain for any new laws.
Law breakers don't say "Hey, I was going to rob this store, rape the women, kill the clerk and leave.......but I had better use a knife this time because guns are illegal"