Since the terrible and senseless murders in that Aurora movie theater, there's been a lot of talk about how to fight back against a mass shooter. It's become a standard talking point that more guns among the victims would have allowed someone to kill any mass shooter, basic tactical realities notwithstanding. And Houston's Department of Public Safety and Homeland Security has recently released an instructional video called "Run. Hide. Fight.," which offers basic tips on surviving "an active shooter event." The shortest, and best, takeaway from the video is that "run, hide, fight" is a list of the best options in order. Getting away is your best hope. Getting behind cover is the second-best hope. But if you can't do either, the grim question is what to do?

I'm not an expert, and won't pretend to be. I'm not in law enforcement. But a few years ago, after one very high-profile mass shooting, there was an anonymous threat to repeat that crime at my workplace on a specific date. Since I was going to be at work that day, in the building that where such a copycat shooting would take place, I thought fairly hard about the mechanics of these shootings, and especially of the specific incident mentioned in the threat. The would-be copycat never showed up, thank God, and now I pass the fruits of my obsessive worrying on to you.

Here's the basic fact: if you are attacked by a shooter in a public place, and if you ever get a chance to stop the shooter by force, you will get that chance when the shooter stops to reload. That is the best opportunity that you could possibly have. It also strengthens your chances if more than one person rushes the shooter, preferably from different directions. But unless the shooter needs to reload, even attacks from multiple directions mean at least one person attacking him will get shot. The pause for reloading really is your best chance.

You are not guaranteed to get that chance, or any chance. You could be shot before he needs to reload. In the case that my copycat threatened to imitate, the shooter had worked out a method for protecting himself during reloading. (I have absolutely no interest in detailing that method.) And if the copycat attack had happened, I would most likely have been on the floor of a basketball arena, while the shooter could potentially have fired from an upper level. Shootings like this unfold randomly, and you're not guaranteed anything. This is one of the many reasons that "run" and "hide" are the go-to strategies.

If you did get a chance to attack the shooter, in that moment when he needs to reload, you would not need a gun to stop him. When he is temporarily unable to fire, he can be attacked with bare hands or hit with anything handy. And there are documented incidents where shooters have been stopped, and further killing prevented, in exactly this way.

On the other hand, if you happened to have a handgun on your person when the shooting started, it still wouldn't help much until the shooter had to reload. Most mass shooters are using semi- or fully-automatic weapons with a high rate of fire, designed to provide suppressing fire that makes it hard for anybody to fire back. That is what "assault rifle" means: it's a rifle designed to assault and overwhelm armed opponents through superior firepower.

The military designed weapons like these so that our soldiers and Marines could limit enemies' ability to fire back at them. And even not-quite-fully-military versions can spray more than enough gunfire to hold off return fire from random civilians with handguns. Of course they can. They're designed to. The point of the assault-weapon ban in the 90s was to limit guns with enough firepower to overwhelm the police. My number one nightmare as a police brat was one of my family having to defend her- or himself with a handgun against someone with an automatic weapon. Even trained professionals who take regular handgun practice aren't properly equipped to fight back against an assault gun.

This is of course before we even consider that the shooter will almost always start shooting before anyone else draws. And having a gun doesn't keep you from taking bullets, or guarantee that you will be in any shape to fire back. Of course not. Carrying a gun does give many people an increased sense of safety, but this is purely psychological: in fact, just an illusion. And if you view carrying a gun as making you safer when you strap it on, you need to rethink things. Guns are not magic amulets. The placebo reassurance they provide can even be dangerous if it keeps you from assessing risks properly.  And having a gun when you're attacked without warning by someone with much, much more firepower is not going to increase your safety a whole lot.

What matters most, then, is how many bullets the shooter has in each magazine. He should need to reload early and often. The fewer bullets he has in each clip, the more opportunities there will be to stop him, and the sooner they will come. Because the grim truth is that you have to concede the shooter his first magazine. Unless the gun jams, he will likely get off every bullet that he has in the clip when he starts shooting. If he has sixty rounds in that clip, he's likely going to get to fire sixty rounds. If he manages to reload, the window on stopping him has closed for another sixty rounds. If he only has ten rounds in each clip, then there's less damage he can do before the brief moment that he becomes vulnerable, and the more of those brief moments of opportunity there will be.

The most sensible policy, given these basic facts, is not to expand concealed-carry laws (which have at best a marginal effect on incidents like this and at worst a merely hypothetical one) but to limit the size of magazines. That won't prevent shootings like this, but will limit the number of people that a shooter can hurt and kill. A smaller magazine allows the killer fewer shots, creates more chances to stop him, and limits his ability to lay down the kind of suppressing fire that prevents people from shooting back at him. (A high-firepower attack eats ammunition fast.) Having a gun won't help you against someone who has dozens of bullets left and can spray them at you rapid-fire. On the other hand, you don't need a gun to stop someone whose gun is empty.

Limiting magazine sizes shouldn't sound like a radical step. We've done it before. The hundred-bullet drum that the Aurora shooter used was illegal just ten years ago. Making them legal again, as the gun lobby insisted, hasn't done a damn thing to prevent crime since then. But it made this crime a lot worse, and made it easier to kill people. If you want to stop people from killing large numbers of their fellow citizens, and I certainly do, it would be a big help to give people fewer shots. The Second Amendment might be complicated. But restricting the sale of large magazines shouldn't be complicated at all.