It is all too common these days for people to use capacity to justify a certain firearm or even a caliber. I personally shiver when people try to make generalizations based on arbitrary information that doesn't even match up to their situation. Some of the studies they cite are based on studies or plain old ballistics gel demonstrations. This should be an interesting thing to discuss. Good old caliber debate analysed peripherally.
When we analyse the necessity of more rounds in our guns, we need to be honest about the root cause of this standard. There are two types of concerns that people worry about. The first scenario is being able to sufficiently engage multiple attackers. Some people feel that a single attacker being engaged may require a certain number of rounds in order to take them out of the fight, even when all rounds are center mass.
This type of scenario is not too common where more than one attacker needs multiple rounds, because typically it is one that takes most of the shots while the rest flee. But in the unlikely event that this is such an issue, the common thought is that you can distribute those rounds evenly between the attackers. The thing that people are missing in this theory is that time is still gonna be the only determining factor to whether the response was adequate and the number of rounds hit where you intended them to hit. In this scenario, you can see that it isn't the number of attackers vs your magazine capacity, but rather the time it takes to take out the threat. If your caliber is not all that effective at penetrating and punching through bone, as is a common failure of the HST, you will need more rounds and more time. Caliber and bullet selection are indeed going to make the difference here. Until that threat stops from choice or internal damage, you are probably going to continue to shoot. Having a million rounds of crappy ammo is not going to stop a determined attacker fast enough.
The next issue people have is the fear that no matter how many rounds they fire, the rounds won't stop the attack IN TIME. So, these armchair operators opt for more rounds, even if they have to downgrade their caliber to something that is not as effective. These people are affectionately referred to as the WHAT IF brigade. Many times, this is just something they imagine or try to justify through third person anecdotes without actually knowing where the shots landed and how they penetrated. If your shots fail to reach the vitals, of course you are gonna have to keep shooting. The whole reason we shoot for the vitals is to cause an immediate drop in blood pressure, which forces the attacker to STOP.
With all that said, there are plenty of studies that show that most of the time, attackers are stopped within 8 rounds. This is the capacity that most people have in a single stack carry pistol like the M&P Shield. For those using full size .45 ACP 1911s, you will easily carry 9 with a flush magazine. With that said, we need to realize that stopping a threat is all about time, shot placement, and bullet design. First, you have to have a bullet that can penetrate to the vitals through bone and any realistic barrier. Next you have to deliver many of these rounds in the right place in as little time as possible. This basically is like continually opening up the flood gates on a dam. The way to open the dam the best is to make bigger holes, which can only happen through using a larger caliber. You can have as many rounds as you want, but if you are loading you pistol with crappy rounds that underpenetrate, you will need a large capacity for sure, and still be good at quick reloads.
In this article, the point I am trying to convey is that there are multiple factors that will determine the outcome of your use of force with a firearm. You have to hit the right area, cause the most damage that you can until the threat is stopped. For this reason, caliber, bullet design, accuracy, speed, and reaction time are going to be crucial. These factors are all individually important and should be considered. Make no mistake. There is more to survival than capacity and you cant use it to make up for a deficiency in skill, reaction time, awareness, discipline, etc. Be mindful of reality, and choose you bullet and caliber design wisely. In the meantime, make sure to practice awareness, and high stress reactions. At the end of the day, that is what will do you the most good.
Do It Rite
Alaska-Based Youtube Vlogger, Retired Marine, gun enthusiast, and passionate firearm and gear evaluator.