Handguns Magazine: Capacity, Size, & Tactical Advantage

Concealed carry forum on tactical advantage during gunfights.

Left: Most gunfights tend to be short and intense events. The possibility of missing is high regardless of how much time you spend “target shooting”. Having a higher capacity magazine will help to keep you in the fight longer. Right: Think of volume of fire (high magazine capacity) in the same way you would look at endurance in a fighter. It allows you to stay in the fight longer.

I suppose this will be yet another highly controversial issue, but what the heck. Controversy makes for interesting discussion, no? The issue is to look at whether high magazine capacity gives you a tactical advantage, or if we are better served by carrying an equally sized weapon with a smaller capacity of bigger bullets. Before I answer my own question, let me put forth some facts as seen both in force-on-force training and on the street.


If we look at the three most prevalent calibers, we see that there is very little difference between them.


Point One

Pistol bullets, regardless of caliber, are all what one colleague calls “iffy.” None can be guaranteed to drop an adversary in his tracks reliably. The notion of a one shot stop is an urban myth, dreamed up by those with a vested interest in such things. I have seen .45s work and fail, and I have seen 9mm both work and fail. For the record, the only one shot drop (excluding head shots) I have ever seen with a pistol was fired by a good friend as we entered a crack house during a SWAT raid. He shot the bad guy squarely in the heart with 9mm +P+ out of a SIG P-226. He only fired once because the bad guy fell before my friend could reset his trigger for the next shot!

If we look at the three most prevalent calibers, we see that there is very little difference between them. A 9mm (also .38/.357) is only one little millimeter smaller than the 10mm (aka .40 S&W), and that is only one little millimeter less than the vaunted 11mm (aka .45 ACP). And before we get into the high speed, light bullet versus the heavy, slow bullet argument, let’s remember that you can only drive a pistol bullet so fast without drastically affecting its integrity. Moreover, since penetration is affected by weight, sacrificing weight for speed will not yield good results. Finally, you can only make a bullet so light or so heavy. There are limits to what you can shoot out of a pistol.

I have seen every one of these calibers fail at one time or another. There are those who disdain the 9mm as unsuitable for anything larger than squirrels. With modern ammunition, this is simply not true. There is also a myth and a cult that has grown up around the .45 ACP in this country. Sadly, it is not the deadly hammer of god that its proponents suggest. This is not new. Read Fairbairn’s Shoot to Live. He writes of two separate times when the .45 failed to work any better than anything else. Although one millimeter may give you a slight edge in a less-than-optimum body hit, under most circumstances, there will be very little difference between the effectiveness of the various calibers when modern, anti-personnel ammo is used. Trauma injury doctors and reputable terminal ballistics experts tend to agree with this statement.

Point Two

Private citizen CCW operators do not go looking for trouble. If they are called to fight, it is either because they have inadvertently crossed paths with bad guys while they are doing bad guy stuff (i.e., walking in on a robbery in progress), or because they have been specifically targeted and stalked (such as a carjacking or home invasion event). They will have to use extreme violence to fight off the surprise attackers. When we translate the conversion of fright and startle into a firearm application, that definition is high volume of fire. You will shoot a lot, and until the threat is no longer there.

While these events share slightly different dynamics, the common thread often seen is that of multiple adversaries. The lone criminal or terrorist is an urban myth. If your fight only involves one, consider yourself lucky. More often than not, you will be outnumbered.


Urban gunfights do not go on for hours. Unexpected, short duration, high intensity, extreme violence and multiple adversaries.


Another point is the time frames in which these events take place. Think three seconds. After this, either you will be dead, or your adversaries will be dead. Urban gunfights do not go on for hours. Unexpected, short duration, high intensity, extreme violence and multiple adversaries. That is the backdrop.

Point Three

Our staff has collectively been in a large number of gunfights, with a range of police, citizen and military events. We draw on those experiences to set up mock gunfights in dynamic, unscripted, force-on-force training drills. Although the surprise factor is missing (you generally don’t know that you will be in a gunfight until it is upon you), the dynamics of its evolution do not change much. Here are some other observations from watching hundreds of those drills:

A) Defenders will fire their weapons until the threat disappears. That means that until the role player falls down (simulating effective hits delivered) or runs away (removing the target), the good guy will keep firing. The concepts of school solutions, controlled pairs, or otherwise artificially limiting the number of shots (as one does in a firing string on the range) do not hold up, even in guys who’ve been extensively trained to do it.

B) When a training gun stops firing (due to running out of pellets), the shooter is still in the fight and still trying to shoot his enemy, as well as trying to avoid being hit by him. We see them continue to try to work the trigger one or two times before there is a realization that there has been a stoppage (malfunction or empty gun). This is followed by a visual examination of the gun, and only then is remedial action taken.

This can take upwards of a second and a half before there is even an attempt to fix the gun, and then there is additional time needed to reload. Thus, the idea that one can read the gun’s feel and immediately realize a need to speed load simply does not hold up. Running out of ammo is usually a fight ender if there has been a failure to stop or there are multiple adversaries at hand.

C) Participants in these reactive mock gunfights are debriefed immediately to get a clear picture of what happened before any rationalization takes place. Besides a “shoot them to the ground” firing process, most shooters do not remember seeing the crystal clear sight pictures they learned on the shooting range. We see a great deal of point shooting, and gun index shooting. I have yet to see anyone strike a classic shooting posture and press off a carefully sighted pair in these room distance drills.


So the question is this: Given that there is a limit to the size of the pistol that one can carry, do I want that pistol to hold more rounds?


The point to remember is that in a fight that the private citizen is likely to be in, one can easily develop “Bullet Deficit Disorder,” which can have deleterious effects on the outcome of that fight. The idea that a pair or trio of quality rounds carefully delivered onto a high scoring target zone will stop the action and fail both the terminal ballistics test and the applications test.

A truth of gun fighting: Having more ammo immediately on board lessens the likelihood of ever needing to reload. Not needing to reload translates into more time delivering lead and less time manipulating the weapon. More trigger time increases the likelihood of hitting, which increases survivability.

So the question is this: Given that there is a limit to the size of the pistol that one can carry, do I want that pistol to hold more rounds? My answer is a strong YES!

Gunfight from a vehicle.

In a surprise attack, such as in a confined space like a vehicle, high volume of fire will help you regain the initiative in the fight.

Consider the similarly sized Glock 36 in .45 ACP, and the Glock 23 in .40 S&W. The latter holds nearly twice the ammo of the former in an almost identical package. The Glock 19 is an even more drastic comparison, with 15 shots available. Of course, there are also high capacity .45 pistols for those so inclined and for those who can wield them. I would argue that if your choice is a .45, a gun holding 13 would be better than a gun holding 6. And if your hand is too small for the 13 shooter, rather than decrease capacity, I’d decrease the caliber.

I have a colleague in South America who has been in high-risk police service for close to three decades. He has been in over three-dozen verified gunfights. His weapon was originally a Browning Hi-Power and later a Glock 17. I was very interested in hearing more, so I asked him about the load he used. He said that he had always used military ball, full metal jacket. Astounded, I asked him why he chose that. He said, “That is all we can get here. Hollow points are illegal.”

I shook my head and told him that there was a belief in the USA that 9mm was an anemic caliber, especially in the load that he chose. He shrugged and said that his adversaries must not have gotten the word. He said that he fired a burst at the chest, and if they didn’t fall fast enough, he fired a burst at the face. He never needed to reload and had enough on board, so if he missed a shot or two, he could catch up in the fight. And before we hear the careful shooter versus the spraying prayer, this man is one of the best shots I have seen and he competes on an international level. Even so, he knows that the chaos in a gunfight can play havoc with even the most gifted marksman. Perhaps we need to take a lesson from him.

Me? I split the difference and carry a Glock 23 in .40 S&W. But I feel just as comfortable with a 15 shot 9mm.

Related: Learn how to improve your handgun accuracy: 101 Accuracy Secrets…


[ Gabriel Suarez is an internationally recognized trainer and lecturer in the field of civilian personal defense. He has written over a dozen books and taught courses in several countries. ]


Suarez International, Inc.
303 E. Gurley St., Ste. 461
Prescott, AZ 86301 USA
(Office) 928-776-4492


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