Magazine Capacity for Self-Defense

[English]

Gabe,
This is in response to your latest and excellent News from Suarez International.

I agree with all of it apart from cartridge choice. In particular, I have argued for a long time that the stress on reloads in most trainer's courses is excessive because in most circumstances if you have to stop for a reload you will be dead before you have completed it. That leads directly to the need for more than six shots. There is not likely to be time to place perfect shots in realistic scenarios. What the shooter must do is place telling shot with minimum delay until the threat ceases to be a threat. If this means going to a smaller caliber to get more shots in the magazine then that is what you should do. For all this I am cheering you on.

You point out that the .45 is not the hammer of Thor that many believe it to be. Here, here say I! (or is it hear, hear?). As you say, pistol rounds are iffy. All can fail and so can many more powerful rifle rounds. You give the example of the .45ACP G36 with six round magazines and compare it to the .40S&W G23 with a 13 round magazine. I have often offered the same comparisson! To be precise the G23 is 0.08 inches longer though its barrel is 0.24 inches longer. It is 0.24 inches taller. It is 0.05 inches, that is 1/20th of an inch thicker. The real down side is that it weighs about 4oz more with a loaded magazine, or about 3oz more if you take the G32 instead, but for that you get 7 more shots. That doesn't seem like a hard decision in a holster rather than pocket carry pistol.

That works realy well for the single stack G36 versus the double stack G23 or G32. In comparison with the double stack G30, all the dimensions are the same as the G36 apart from weight and thickness and 9 rounds instead of 6. The thickness goes up 0.14 inches, that is a sixth of an inch but the G36 fans say it makes a real difference. The weight goes up nearly six ounces and I think six ounces is significant for carry but that it is is a clear victory to the G23/32 again. I think that the .45 is just that critical bit too fat to get enough in a reasonably sized grip frame for concealed carry.

When we compare the G23/32 to the G19, obviously the linear dimensions stay the same and the G32 is about 1/5th of an ounce heavier than the G19 and the G23 just over an ounce heavier. No difference there worth bothering about so all that is left is 15 round magazines in the G19 versus 13 rounds in the G23/32. Is the extra whatever in the .40 and 357 over the 9mm enough to compensate for two more rounds? That is 15% more rounds per 9mm magazine or 14% more in the pistol if you top off!

The force on force evidence is that people pull the trigger twice or even three times after the pistol stops firing and before looking to see that the pistol is not jammed or empty. In contrast to that, your good friend with the 9mm one shot stop that you witnessed did not have time to pull the trigger a second time before the BG dropped. (It has to be worth noting that whatever caused that rapid drop it was not the lack of flow from the heart because that takes a lot longer and it is aslo worth noting that the 115gn 9mm+P+ is a lot closer to 357SIG performance than to ordinary 9mm)

The difficulty with these two pieces of information is that someone shot with a real handgun bullet will usually react far more visibly than someone shot with a BB and the person firing the real handgun is much more aware of the recoil, or lack of it than the person firing the airsoft. If we are fighting multiple adversaries, the important question is the average number of shots that it takes in real circumstances before we see an obvious indication that the BG is out of the fight and whether we have time to stop the next shot after that and transition to the next BG? (Or are we better firing a pair on one and then a pair of the next and so on before coming back to finish off?)

What this comes down to, more or less, is whether, say, 2 shots with .40 or 357 will be as good as 3 shots with a 9, or is 3 equivalent to 4, or 4 to 5 or even 5 to 6 or 6 to 7? Even at a six to seven equivalence the magazine capacities are equivalent in the 23/32 to 19 comparisson against two opponents. The 4 to 5 equivalence is good enough for three opponents and the 3 to 4 is needed for four opponents though that leaves you with two spare rounds in the 23/32. It is my guess that the true equivalence is quite a way down the scale. Maybe 3 to 4 or even close to 2 to 3.

We can be in no doubt about three things. One is that there are no magic bullets and the second is that some cartridges are better than others though it is very hard to decide by how much. The third depends on what different people mean by a one shot stop. I think it is clear that there are some one shot stops and you give an example of one. I think some people think that some cartridges produce all one shot stops and that is clearly nonsense. The only thing to dispute is not whether one shot stops exist but whether a cartridge will produce more of them than some other cartridge and if it does, how often does it happen. This might be an interesting question but we can agree for now that it does not happen often enough to rely on so we won't rely on it. That means that the third thing with no doubt is that one shot stops exist but we know of no way to rely on them with any cartridge we know that is likely to be fired in a handgun.

You talk of there being little difference between 9mm, 10mm (.400), and 11.25 mm (.45) as sizes of holes in bodies and still I agree with you BUT I don't think that bullets make caliber sized holes in people and this is my disagreement.

A reasonably high speed bullet produces a pressure field in front of it and to the sides of it as it pushes tissue out of the way to make room for its passage. This pressure field squashes the cells in front of it roughly in line with lines radiating out from the middle of its nose. At right angles to those lines it stretches cells. This bursts the cells close to the bullet and turns them to mush or puree. This liquid then flows round the sides of the bullet and adds to the sideways pressure field. This pureed volume is what makes up the permanent cavity and it is often called the crush cavity because the tissue is crushed to puree. For part of the bullet track this is almost invariably larger in diameter than the expanded caliber of the bullet. All that tissue thown to the side has inertia and it keeps going till the surounding flesh bounces it back. The limit of this movement makes up what is generally called the temporary cavity.

The flesh around the temporary cavity has some elasticity but it also tears. In effect all torn muscle is muscle that is out of action for weeks or months or for ever. The important thing is that it is no longer in the fight NOW. Beyond that zone there is tissue that is not torn but is bruised and probably numbed. That is tissue which is out of the fight for maybe only a second or two or maybe quite a number of seconds, depending on how close it is to the tear zone. Its nerves sending and receiving messages stop working and take time to recover. As far as we are concerned those few seconds are of critical importance in a fight that last 3 to 5 seconds where we want to disrupt as much of our oponent's fighting capability as possible.

So as far as we are concerned the damage done by a bullet extends some way out from the permanent or crush cavity and we can see from ballistic gellatine tests that the permanent cavity damage is not at all well related to the caliber or the expanded caliber of the bullet. This is because the damage done is caused by a combination of velocity and expanded caliber. As illustration of this the typical pictures of 357SIG and .45ACP in gellatine are remarkably similar. What is equally clear is that the 9mm tracks, and especially the 147gn 9mm tracks show a lot less damage - perhaps less than half as much. My calculation comes to a ratio of 2.2:1 in favour of the 357SIG. It is also significant that these pictures also show consistently that the end of the track is narrower by something like half of the expanded diameter of the bullet. In other words, at lower speeds the bullet tears the tissue in front of it, passes through the tear with some stretch of the tissue and the tissue then closes up behind it.

It is hard to determine the relationship between volume of damage done per shot and the cumulative probability of being enough to stop a fight but I would guess that it is quite close. If, as seems to be the case, the 357SIG does about 2.2 times the damage of a 147gn 9mm I would gues that about half as many sound hits with the 357 as with the 147 gn 9mm would bring the fight to an end even though sometimes that would be one shot and somtimes it would be six shots. At a guess the relationship between the 357 and the 115gn 9mm is about 1.5:1 and so I would guess that two 357s would do as well as three 115gn 9mms.

I am a little less accurate with the 357 than with a 9mm but not enough to matter at majority combat type distances and I can certainly fire two shots of 357 a lot faster than three shots of 9mm. The first shot obviously gets away in the same elapsed time for both and the second shot from the 357 is only marginally behind the the time for the 9mm. This does not make the 357SIG a magic bullet but to my mind it does make it a better compromise and well worth the drop to 13 round magazines from 15 round magazines.

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