Perhaps Tacitus X would ban all guns except single shot ones or revolvers. Those require removal and reloading of the rounds, providing a window of opportunity to disarm the perpetrator. Of course, it is highly improbable and literally impossible to "unmake the soup." As is true with nuclear weapons, once you have a working model, merely banning it is an exercise in futility. Automatic weapons won't magically disappear when they are banned, They will merely show up in the hands of the worst people-the criminals who don't obey the laws in the first place.