When it comes to the “Arms” protected by the Second Amendment, the conceptual space is typically divided into two categories. Some weapons, like those that are “dangerous and unusual,” can be banned without raising any constitutional problems. For those that are not dangerous and unusual, the government has to satisfy some requisite level of scrutiny. But—and I hate to do this again, having just made a conceptually similar argument about the Two Part test—there also seems to be a third category: Weapons that cannot be banned without categorically violating the Second Amendment.