I have a sincere question for concealed/open carry advocates or anyone else who cares to hazard a guess.

This is going to require one assumption – that the point of carrying a gun, concealed or otherwise, is to have it available for self defense (mugging, etc.) or to intervene in a Virginia Tech-type spree shooting incident. You know, the Heroic Bystander, Good Guy With Gun Stops Bad Guy With Gun thing the NRA and its water-carriers are always talking about.

As we are constantly reminded from casually following the news over time, The Police aren't great shots. Perhaps they are the best possible shots under the circumstances in which they shoot, but even if so the statistics show that their best is pretty bad. It is hard to find comprehensive statistics on police discharging their guns, so information from the FBI and individual departments has to stand in. Consider this:

According to a 2008 RAND Corporation study evaluating the New York Police Department’s firearm training, between 1998 and 2006, the average hit rate during gunfights was just 18 percent. When suspects did not return fire, police officers hit their targets 30 percent of the time.

This is particularly alarming when one considers that:

The NYPD has some of the most comprehensive and sophisticated firearms training of any police force in the country, using a combination of live fire, non-lethal force and simulated scenarios.

It stands to reason that officers in smaller departments with fewer resources and less rigorous training would fare worse. However, lacking better data let us assume that the NYPD numbers – about 1 in 5 bullets in firefights and 1 in 3 otherwise – are roughly representative of the nation. This likely gives cops more credit for accuracy than they deserve, but let's run with it.

The majority of bullets that miss the intended target presumably hit nothing, and a minority of them hit bystanders. The reverse could not be true unless the police fired into a densely packed crowd, which is possible but unlikely. This is to say that police inaccuracy creates some non-zero risk for bystanders and the public in general. Missed shots, in short, are a bad thing.

The police have many, many benefits that a civilian carrier would not. Their firearms, if we use the NYPD as an example, are expensive automatic pistols designed for accuracy (limiting recoil, for example) and in calibers (9mm, .380 ACP, etc.) chosen specifically to avoid over-penetration (Which concealed carriers also tend to avoid. Zing!) if the bullet misses the target. The police, in other words, are shooting with weapons chosen specifically, usually through extensive trials and testing, to give them the greatest possible chance of hitting the target and not harming anyone else. They're not blazing away with .44 and .357 revolvers like in the cop movies from the 1970s. Check out the prices on the handguns your local PD uses – usually H&K, Sig, or Glock. Not cheap, are they?

So. With everything factored in to maximize accuracy, the police are still really goddamn inaccurate.

At long last we come to my question: If this is the police performance, how accurate do you think civilian carriers would be in any situation in which using their gun was justified? Let's say a mugger accosts them in a dark street or a man with a gun starts shooting up their office building.

In contrast to the police, civilian shooters have no formal training for using a gun in a "live", stressful situation. Often they have no formal training, period. Civilian shooters also have a variety of weapons ranging from state-of-the-art to Grandpappy's Old Six Shooter. They also have a tendency to own, and perhaps carry, firearms that are ludicrously overpowered for any practical use. Flip through a handgun magazine at the bookstore and look at some of the shit being advertised and written about. My stepbrother has a Desert Eagle. The last time I went to a shooting range, one of my acquaintances was plugging away with a .454 Casull revolver suitable for killing elephants or shooting down Russian helicopters. Anecdotes? Yes. Rare? I doubt it.

Leaving aside the question of how the police are supposed to tell The Shooter apart from a civilian carrier who is plugging away in the middle of a spree shooting, what percentage of bullets fired by bystanders can we expect to hit an intended target rather than coming to some other, potentially dangerous end? It's hard to imagine how they could conceivably exceed the performance of the police – performing under duress is a bitch, after all – so that 18% figure for the NYPD would seem to be the absolute upper limit.

My guess (and I'd love to know if any data are available) that something on the order of 5% of bullets fired by non-law enforcement shooters hit the intended target. I'm inclined to guess lower, but since we're being generous with the police figures let's extend the same courtesy to carriers.