Greg Ellifritz has been interested in handgun stopping power for some time, and now he’s done his own research:
I think the most interesting statistic is the percentage of people who stopped with one shot to the torso or head. There wasn’t much variation between calibers. Between the most common defensive calibers (.38, 9mm, .40, and .45) there was a spread of only eight percentage points. No matter what gun you are shooting, you can only expect a little more than half of the people you shoot to be immediately incapacitated by your first hit.
The average number of rounds until incapacitation was also remarkably similar between calibers. All the common defensive calibers required around 2 rounds on average to incapacitate.
Something else to look at here is the question of how fast can the rounds be fired out of each gun. The .38 SPL probably has the slowest rate of fire (long double action revolver trigger pulls and stout recoil in small revolvers) and the fewest rounds fired to get an incapacitation (1.87). Conversely the 9mm can probably be fired fastest of the common calibers and it had the most rounds fired to get an incapacitation (2.45). The .40 (2.36) and the .45 (2.08) split the difference.
It is my personal belief that there really isn’t much difference between each of these calibers. It is only the fact that some guns can be fired faster than others that causes the perceived difference in stopping power. If a person takes an average of 5 seconds to stop after being hit, the defender who shoots a lighter recoiling gun can get more hits in that time period. It could be that fewer rounds would have stopped the attacker (given enough time) but the ability to fire more quickly resulted in more hits being put onto the attacker. It may not have anything to do with the stopping power of the round.
Another data piece that leads me to believe that the majority of commonly carried defensive rounds are similar in stopping power is the fact that all four have very similar failure rates. If you look at the percentage of shootings that did not result in incapacitation, the numbers are almost identical. The .38, 9mm, .40, and .45 all had failure rates of between 13% and 17%.
For Ellifritz there really isn’t a stopping power debate:
All handguns suck! If you want to stop someone, use a rifle or shotgun!
What matters even more than caliber is shot placement. Across all calibers, if you break down the incapacitations based on where the bullet hit you will see some useful information.
Head shots = 75% immediate incapacitation
Torso shots = 41% immediate incapacitation
Extremity shots (arms and legs) = 14% immediate incapacitation.No matter which caliber you use, you have to hit something important in order to stop someone!
Here’s some of the data:
.22 (short, long and long rifle)
# of people shot – 154
# of hits – 213
% of hits that were fatal – 34%
Average number of rounds until incapacitation – 1.38
% of people who were not incapacitated – 31%
One-shot-stop % – 31%
Accuracy (head and torso hits) – 76%
% actually incapacitated by one shot (torso or head hit) – 60%.380 ACP
# of people shot – 85
# of hits – 150
% of hits that were fatal – 29%
Average number of rounds until incapacitation – 1.76
% of people who were not incapacitated – 16%
One-shot-stop % – 44%
Accuracy (head and torso hits) – 76%
% actually incapacitated by one shot (torso or head hit) – 62%.38 Special
# of people shot – 199
# of hits – 373
% of hits that were fatal – 29%
Average number of rounds until incapacitation – 1.87
% of people who were not incapacitated – 17%
One-shot-stop % – 39%
Accuracy (head and torso hits) – 76%
% actually incapacitated by one shot (torso or head hit) – 55%9mm Luger
# of people shot – 456
# of hits – 1121
% of hits that were fatal – 24%
Average number of rounds until incapacitation – 2.45
% of people who were not incapacitated – 13%
One-shot-stop % – 34%
Accuracy (head and torso hits) – 74%
% actually incapacitated by one shot (torso or head hit) – 47%.357 (both magnum and Sig)
# of people shot – 105
# of hits – 179
% of hits that were fatal – 34%
Average number of rounds until incapacitation – 1.7
% of people who were not incapacitated – 9%
One-shot-stop % – 44%
Accuracy (head and torso hits) – 81%
% actually incapacitated by one shot (torso or head hit) – 61%.40 S&W
# of people shot – 188
# of hits – 443
% of hits that were fatal – 25%
Average number of rounds until incapacitation – 2.36
% of people who were not incapacitated – 13%
One-shot-stop % – 45%
Accuracy (head and torso hits) – 76%
% actually incapacitated by one shot (torso or head hit) – 52%.45 ACP
# of people shot – 209
# of hits – 436
% of hits that were fatal – 29%
Average number of rounds until incapacitation – 2.08
% of people who were not incapacitated – 14%
One-shot-stop % – 39%
Accuracy (head and torso hits) – 85%
% actually incapacitated by one shot (torso or head hit) – 51%Rifle (all Centerfire)
# of people shot – 126
# of hits – 176
% of hits that were fatal – 68%
Average number of rounds until incapacitation – 1.4
% of people who were not incapacitated – 9%
One-shot-stop % – 58%
Accuracy (head and torso hits) – 81%
% actually incapacitated by one shot (torso or head hit) – 80%Shotgun (All, but 90% of results were 12 gauge)
# of people shot – 146
# of hits – 178
% of hits that were fatal – 65%
Average number of rounds until incapacitation – 1.22
% of people who were not incapacitated – 12%
One-shot-stop % – 58%
Accuracy (head and torso hits) – 84%
% actually incapacitated by one shot (torso or head hit) – 86%