The Firing Line Forums - View Single Post - One reason why we need more than 10 rounds...

**JohnKSa** · January 17, 2013, 11:53 PM

One of the questions I'm hearing frequently is antis asking why anyone needs high-capacity magazines.

Awhile back I did some thinking about multiple assailants and what happens when one factors in the likelihood that misses are probable in a real-world shooting. I decided to run the probabilities. The results were eye-opening. Maybe some of the results will be useful.

You have to assume a hit rate and I used 30% for the initial scenario since it is a fairly representative hit rate for LEOs in gunfights. Most experts will tell you that it's a good idea to plan that it will take at least 2 solid hits to properly pacify a determined aggressor, so I set the scenario up to require 2 hits per assailant.

In a scenario with 2 attackers and an assumed hit-rate of 30%, 10 rounds gives the defender about a 35% chance of making 2 hits on 2 opponents before the gun runs dry.

In the same scenario, same number of attackers, same hit rate, 15 rounds give the defender about a 70% chance of making 2 hits on 2 opponents before the gun runs dry.

The extra 5 rounds change the scenario from one where the defender fails nearly 2/3rds of the time to one where the defender succeeds almost 3/4ths of the time.

There are some other assumptions inherent in trying to apply these probabilities practically. For one thing, it assumes that the defender is able to tell how many hits have been made on the first assailant and then immediately switch to shooting at the second assailant after making 2 hits on the first--wasting no additional shots on an already neutralized opponent.

The assumption is made that the defender is able to empty his/her weapon in the course of the gunfight--he/she is not incapacitated before that can take place.

The assumption is made that 2 hits disable the attacker, and further that the attackers keep attacking until disabled. Obviously, sometimes attackers run away in the real world.

In effect, the math assumes a sort of best case scenario. In other words, with a hit rate of 30% the defender might do worse than the numbers suggest, but it's pretty unlikely that they would do better if both attackers don't give up until they're disabled by 2 hits.

Here's the original thread.

http://thefiringline.com/forums/showthread.php?t=494257

January 17, 2013, 11:53 PM	#1
JohnKSa Staff Join Date: February 12, 2001 Location: DFW Area Posts: 24,990	One reason why we need more than 10 rounds... One of the questions I'm hearing frequently is antis asking why anyone needs high-capacity magazines. Awhile back I did some thinking about multiple assailants and what happens when one factors in the likelihood that misses are probable in a real-world shooting. I decided to run the probabilities. The results were eye-opening. Maybe some of the results will be useful. You have to assume a hit rate and I used 30% for the initial scenario since it is a fairly representative hit rate for LEOs in gunfights. Most experts will tell you that it's a good idea to plan that it will take at least 2 solid hits to properly pacify a determined aggressor, so I set the scenario up to require 2 hits per assailant. In a scenario with 2 attackers and an assumed hit-rate of 30%, 10 rounds gives the defender about a 35% chance of making 2 hits on 2 opponents before the gun runs dry. In the same scenario, same number of attackers, same hit rate, 15 rounds give the defender about a 70% chance of making 2 hits on 2 opponents before the gun runs dry. The extra 5 rounds change the scenario from one where the defender fails nearly 2/3rds of the time to one where the defender succeeds almost 3/4ths of the time. There are some other assumptions inherent in trying to apply these probabilities practically. For one thing, it assumes that the defender is able to tell how many hits have been made on the first assailant and then immediately switch to shooting at the second assailant after making 2 hits on the first--wasting no additional shots on an already neutralized opponent. The assumption is made that the defender is able to empty his/her weapon in the course of the gunfight--he/she is not incapacitated before that can take place. The assumption is made that 2 hits disable the attacker, and further that the attackers keep attacking until disabled. Obviously, sometimes attackers run away in the real world. In effect, the math assumes a sort of best case scenario. In other words, with a hit rate of 30% the defender might do worse than the numbers suggest, but it's pretty unlikely that they would do better if both attackers don't give up until they're disabled by 2 hits. Here's the original thread. http://thefiringline.com/forums/showthread.php?t=494257 __________________ Do you know about the TEXAS State Rifle Association?