On the gun issue that seems to be the flotation device of this thread, I think they should make bullets extremely exspensive for firearms used for other than hunting i.e. handguns, semi-auto handguns/rifles, and of course fully automatic firearms. Atleast that way anyone looking to harm of this nature (god forbid, it NEVER happens on this scale again) would have a lot harder time trying to conceal a hunting rifle.
Aside from the people who have legitimate uses for ammo, that idea is almost workable. The only problem is ammo sizes where a rifle and a pistol use the same size. A .22 comes to mind, though I'm sure there are many others.
[edit:] And another thought: people can still roll their own when it comes to ammo. Reloading equipment runs at a couple hundred bucks IIRC, but it's even cheaper in the long run (again, for legitimate uses... else there wouldn't be much of a long run)