There’s something I’ve been meaning to ask gun advocates for the last two weeks.

Remember the shootout in Watertown on Thursday, April 18th, between the Tsarnaev brothers and several branches of law enforcement? Reports said there were over 200 rounds exchanged that night, and we learned later that the Tsarnaevs only had one gun, a Ruger 9mm, which holds 15 bullets in its clip. Even if Tamarlan Tsarnaev went through several clips, the majority of ammunition fired came from guns in the hands of police officers who had been trained in the use of their weapons. Even if it wasn’t the majority, let’s make it half and you have a hundred shots fired at two suspects.

How many of those shots hit their targets? Not enough to kill either of them right away. Tamerlan was certainly shot a couple of times, but didn’t die until his younger brother, trying to escape, drove an SUV over him and dragged him along the ground. We know that Dzokhar was shot, too, but only once or twice — most of those 100+ rounds fired by police did not hit the brothers. Fortunately, they didn’t hit any innocent bystanders, either.

And yet, the next day, during the search for the surviving brother, I heard more than one cable pundit or talk radio host say, “I bet those people in Watertown all wish they had a gun right now.” The implication being that if they were armed, they’d be able to kill or capture Dzhokhar and save the day. Because in their gun-obsessed world, everyone with a weapon is a crack shot, a good guy who always gets the bad guy.

Except of course for the MIT police officer Sean Collier and MBTA police officer Richard Donahue. The former was killed and the latter was critically wounded — despite each of them having a gun.

Because that’s how the real world works.