Perhaps a better question is: “how many rounds do I need in my CCW?“. Setting aside IF you’ll need it, here is some interesting data from real world self-defense encounters. I found it very enlightening and learned a lot while researching it.
NOTE: This article does NOT deal with the likelihood of needing your CCW. It assumes you’re in a situation that requires it.
How many rounds do you need in your Concealed Carry pistol?
I love the saying “form follows function”, so lets start by talking about goals a little bit.
Remember that the goal isn’t to kill your attacker, the goal is to make him stop attacking.
Both legally and ethically you have no legitimate reason to do anything more. You are allowed to use lethal force only when a reasonable person would believe you are in danger of grave bodily harm or death. (disclaimer, I’m not a lawyer and that’s not legal advice so please don’t take it as such)
The good news is you don’t have to kill an attacker to make them stop. In fact, John R. Lott says this on page 3 of his book “More Guns, Less Crime“:
“If national surveys are correct, 98 percent of the time that people use guns defensively, they merely have to brandish a weapon to break off an attack.“
So 98% percent of the time, even an empty gun will work… In theory. (I won’t be the one to test that theory.)
But what about the other 2%? Lets say you are in the small minority that need to shoot their concealed carry pistol in self defense.
How many rounds do you need to stop an attacker?
“In a certain (fairly high) percentage of shootings, people stop their aggressive actions after being hit with one round regardless of caliber or shot placement. These people are likely NOT physically incapacitated by the bullet. They just don’t want to be shot anymore and give up! Call it a psychological stop if you will.”
So in the vast majority of self defense shootings, you only need to hit the attacker once. That’s really good news for us good guys… Until you look at some hit percentages in shootings. According to a Study of the NYPD by the Rand Corporation.
Between 1998 and 2006, the average [officer] hit rate was 18 percent for gunfights.
18 percent translates to 5.55 rounds on average to hit the bad guy just once.
If you shoot as well as the NYPD, you need to fire 5.55 rounds on average to hit the bad guy just one time.
But you have to remember, that’s an average.
An average (by definition) requires numbers that are higher and lower. So while you might hit twice in 6 shots, you also might need to fire 8 or 10 or more times to hit just once.
Think about dice if you want to understand this better. Pick any number on 6-sided dice to represent a hit, then go ahead and roll it until you get a “hit”. Sometimes, you’ll roll you your “hit” number 2 0r 3 times in six rolls. But just as often it’ll take 8 or 10 rolls (or more) to make a “hit”.
Now, lets see how many rounds it ACTUALLY takes to stop someone.
As mentioned above, often a single hit will make your attacker give up and/or run away. However, not all attackers will do that.
When a single hit doesn’t convince them to stop, you’ll need more rounds to make them stop. And by make them stop, I mean inflict enough damage that they no longer pose a grave threat to life and limb.
How many rounds does that take for the average person?
Fortunately, we have some data to look at from An Alternative Look at Handgun Stopping Power. It takes 2.45 rounds with a 9mm pistol on average to end the threat.
To be clear, that’s 2.45 Hits – not rounds fired.
- If it takes (on average) 5.55 shots to make a hit,
- And if it takes (on average) 2.45 hits to incapacitate an attacker,
- Then it takes 5.55 x 2.45 = 13.6 rounds fired (on average) to incapacitate an attacker.
Yeah, I was surprised too.
And that’s for only ONE attacker.
If there’s two or three, then it’s double or triple that number… Kind of. (I’ll show you more stats to muddy the waters in a minute.)
I talk about this a little in my article on terminal ballistics, but pistols are horrible weapons for stopping people. Basically, pistols only “poke holes” so poking those holes in the right place is Absolutely Crucial.
When I started writing this article, I was fairly comfortable with the 12 rounds in my modified Glock 34. Now, I might start carrying a spare magazine.
Because that 13.6 number is an average.
An average by definition means it will often take more than the average number of rounds. It might take fewer rounds, but I’d rather have a few extra rounds than desperately need more rounds and not have them.
So if there’s two attackers and adrenaline affects my aim…
You get the picture.
(NOTE: I’m a pretty good shot and do WAY better than 18% at the range. However, I’ve never had the adrenaline from a life-threatening encounter affecting my aim before.)
But what about bigger cartridges like the 40 S&W and the .45 ACP?
I’m glad you asked.
According to the FBI’s justification for going back to 9mm:
“The majority of FBI shooters are both FASTER in shot strings fired and more ACCURATE with shooting a 9mm Luger vs shooting a .40 S&W (similar sized weapons)“
It’s the “more accurate” part that will kill the average performance of the larger cartridges.
Most shooters will be faster and more accurate with a 9mm simply because there is less recoil. Less recoil means back on target faster, less upset of the gun, and lower likelihood of shooter flinch.
The FBI bears this out in their testing.
So the odds are good you’ll be more accurate with the 9mm, but how much more accurate?
For the sake of this article, lets say there’s a 10% accuracy penalty going from 9mm to 40 S&W, and 20% going from 9mm to 45 ACP. (I think it’s probably much more, but I’m trying to be unbiased.)
Rounding slightly, we get 6 shots to score one hit with the 40 S&W and 6.5 shots to score one hit with the 45 ACP. Fortunately, the same article that gave stats for 9mm also has them for 40 S&W and 45 ACP. The 40 S&W takes 2.36 rounds to stop on average, and the 45 takes 2.08 rounds to stop on average.
Doing a little math we get:
- 13.6 rounds for 9mm
- 14.16 rounds for 40 S&W
- 13.52 rounds for 45 ACP
Really, the numbers change very little. (But it’s a LOT easier to conceal 14 rounds of 9mm than 14 rounds of 45 ACP.) This reinforces what I said in my 9 vs 40 vs 45 article; there’s almost no difference in performance between the three.
And please remember, these are averages. A single round to the brain will instantly end any gunfight. But a .500 S&W magnum to the pinky finger won’t do much.
You just can’t miss fast enough to win a gunfight.
Now lets throw a big old wrench in those numbers…
The commonly quoted stats for a civilian self-defense scenario is “3 rounds at 3 yards in 3 seconds“.
I’ve done a bunch of research and it seems they aren’t hard statistics. Rather, the NYPD firearms expert Frank McGee said that’s how the typical police gunfight happened. What happens with the police may not translate well to civilians because they are often looking for bad guys.
Civilians shouldn’t ever do that.
I copied an excerpt from Analysis of Five Years of Armed Encounters and pasted it below. They pulled five years worth of the NRA’s “Armed Citizen” articles and found:
The average and median number of shots fired was 2. When more than 2 shots were fired, it generally appeared that the defender’s initial response was to fire until empty. It appears that revolver shooters are more likely to empty their guns than autoloader shooters.
Now remember, this ONLY includes success stories. It does not include events where the attacker killed the law-abiding citizen.
Of the 482 incidents, here’s what they found about reloading:
Reloading was required in only 3 incidents. One of those involved killing an escaped lion with a .32 caliber revolver, which was eventually successful after 13 shots.
2 incidents out of 482 (I’m not counting the lion) is pretty darn rare. So maybe I don’t need to carry those two spare mags…
Or do I?
I am a cautious person by nature, and would prefer to walk on the safe side of these numbers. I’ve never heard of gunfight survivor who said “I should’ve carried less ammo“. I also wonder how many good guys found themselves with their slide locked back and advancing attackers.
A retired police detective sergeant left this comment (excerpt below) on a review of the Kel-tek PF9:
In one case, a citizen unloaded his handgun on his robber, killing him. He carried NO spare ammo. As he waited for police to arrive, a friend of the robber walked up, asked who shot his buddy, was told the citizen standing by, and then the friend promptly shot the citizen to death, as he stood with his empty gun and NO SPARE AMMO to reload for protection against just such events.
Maybe that’s a statistical outlier, maybe it’s not.
I honestly have no idea.
It’s easiest to collect data when the good guys win, but what about when they lose? We have much less data on those encounters because dead men tell no tales. Maybe they’d say they needed more ammo. Maybe it wouldn’t have mattered.
There’s no way to know.
There’s an old rule we can apply to statistical analysis that goes: “garbage in, garbage out“. The problem with any statistical analysis is getting good data.
How often will it take a single bullet to make an attacker leave vs. how often will it take 13+ rounds (on average) to end the threat?
There’s simply no way to know for sure, so I’ll walk on the prepared side.
I plan to start carrying at least one backup magazine, possibly two. Since I have three 17 round mags from my G34 collecting dust, it’ll probably be them.
Regardless of the size of your pistol, I HIGHLY recommend packing at least one spare magazine. This goes double if you carry a single stack with a 6-7 round capacity.
Will you need it?
But I’d rather not trust my life to “probably”. The worst case scenario is I carry a magazine around and never use it. However, if my gun runs dry and there’s still a bad guy trying to kill me…
That’s why I think it’s a good idea to carry a lot of rounds in your concealed carry pistol and a spare mag. To quote the concealed carry motto: “It’s better to have it and not need it, than need it and not have it.“