This is going back a few pages, but I think the argument that the founding fathers couldn't conceive of assault weapons is a weak one. Context is important. The founding fathers had just undergone a war, as citizens, against a professional military in order to achieve independence. Many, many Constitutional scholars argue that the 2nd amendment wasn't just about national defense - it was a safeguard against the new government becoming tyrannical itself. I would guess that the founding fathers would not have wanted to see any weapons banned. Their stance would have been that citizens should have access to weapons of similar capabilities to what the military has in order to assure the freedom of the citizens and the potential for another revolution if it became necessary. I'm not arguing that this is necessarily a justification for keeping assault weapons legal. The world has changed, and what the founding fathers envisioned doesn't always apply anymore. Women vote. There is a large and expensive standing military. Britain is our closest ally. But please don't try to tell me that assault weapons aren't covered by the 2nd amendment because the Founding Fathers didn't know they would exist - if they had, they almost certainly would have allowed them.
The real reason I'm not entirely certain banning assault weapons would save many lives is that the vast majority of gun-related deaths in this country are perpetrated with handguns. The assault weapons make the biggest headlines, but the recent incident accounted for about 1 normal day's worth of gun deaths. Realistically it isn't assault weapons that are really the big problem. Of course, the point remains that high-powered assault weapons have no meaningful practical application. Other guns that many gun-control advocates want to see banned arguably do. Nobody needs an AKanything or an Manything for hunting or self-defense. The truth is, though, that if somebody wants one badly enough they'll still be able to get their hands on them. I know of 2 people who had access to banned weapons during the previous ban, and my guess is that many of you knew people like this as well. You think one couldn't find its way into an underground sale and wind up in the hands of someone who wanted to use it to kill a few dozen people? With the guns already in circulation, and certainly more than a few unregistered or no longer with the registered owners, banning them isn't going to totally remove them, and people who want them badly enough will find a way to get them. The vast majority of these mass killings involve a suicide. In that case cost isn't really an issue up to the level of one's full net worth, including house, vehicle, etc.