> they need the extra killing power of an assault rifle.
First off, assault rifles are already banned. Assault rifles have at least one mode where they fire more than one bullet per trigger press.
The "assault *weapon*" bans ban scary features. A bayonet lug, for example, does nothing to the lethality of a gun.
As for the magazine size restrictions, there's a big difference between a self-defense situation and premeditated mass-murder. As recent events have shown, you can put 5 bullets in an attacker, and have him still be functional enough to drive away. Had the burglar not been alone, she and her kids would have been defenseless. In self-defense situations, one often doesn't have a spare magazine, and reloading under that kind of stress is a difficult proposition.
I've personally been in a position with my wife where we had a carload of individuals hollering at us and trying to chase us down and box us in in their car. We managed to keep them on the other side side of the road median, we were luckily close enough to make it to a store, we were lucky enough that they didn't follow us in, and we were lucky that the cops came quickly. I don't know what they wanted, but it wasn't good. One of my sisters was raped about the same time of night by a stranger, and LGBT people are regularly victims of violence.
Had I been forced to defend myself and my wife, there's a big difference between facing four assailants with 5 bullets, and facing four assailants with a larger magazine (like the one that came stock with my current pistol). Someone who is planning a mass murder is free to pre-load as many magazines as they want, like the Virginia Tech shooter (who used standard capacity magazines, including 10 round magazines, which are legal even under states with strict size regulations). Even NY's new 7 round limit grandfathers in pre-ban 10 round magazines, ensuring even the rather strict new laws still wouldn't have limited his ability to go on the rampage he did).
The sandy hook shooter was shooting children, and ended his life as soon as emergency services arrived. An extra few seconds spent reloading in a classroom wouldn't have made a difference. He killed 26 people in about 20 minutes, and even a bolt-action rifle can easily accommodate that.
> Your argument is basically this: we shouldn't ban hand grenades or rocket propelled grenades because some asshole can always make some sarin or fly an airplane into a building using a box cutter.
No. The argument is that politicians are basically saying "Something must be done! This is something, therefore, it must be done!", while none of the offered "solutions" would actually do anything to prevent the problem they are claiming to try to.