The trouble here, still, is that the argument you are presenting favors "doing something" over doing the right thing.
The purpose of guns isn't just to kill as many people as possible as fast as possible. Most guns never actually kill anyone at all (even ignoring the observation that it's the person pulling the trigger that kills).
The thing is that if you were to give 1,000,000 law-abiding citizens a fully automatic machine gun and as much ammunition as they could dream of, the murder rate would not go up one iota. Why? Because of that little kicker in the phrase, "law-abiding citizens". You could give a law-abiding citizen a thermonuclear warhead and not have to worry about them destroying a city. On the other hand, in the hands of a bad person all sorts of things become dangerous weapons. A baseball bat, a kitchen knife, a brick, a length of barbed wire, a screwdriver, even a pencil can become a stabbing weapon at a push. And therein lies the problem - the focus is always coming back to ways to rein in the law-abiding (which offers minimal benefit) rather than ways to stop the bad people from doing what they want.
Although the classic NRA line "the solution to a bad guy with a gun is a good guy with a gun" is arguably a little tired the simple reality is that bad people do bad things and, since an open and free society is always vulnerable to the bad people within it, the focus has to be on stopping them as fast as possible. If the bad guy is on a rampage, whether with an AR-15, a meat cleaver, a bag full of pipe bombs or whatever else, they aren't going to be stopped by a concerned citizen armed with a stick.