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The handgun caliber debate.

I am seeing a lot of discussion and comments about handgun calibers (I don’t think you can talk about guns on the internet without debating caliber) at Marko’s and SayUncle.

As I previously quoted John Holschen:

No common defensive handgun cartridge will quickly and reliably stop a human being who is committed to causing serious bodily harm, unless the bullet from that cartridge is applied to the correct anatomy.

Handgun bullets move too slowly to do anything other than create wound channels the diameter of the (expanded) projectile. Adding another hundred feet per second of velocity or another 3mm of diameter doesn’t really make enough difference to matter. Until you get your handgun rounds moving at more than 2500-3000 fps they aren’t going to do anything different than destroy the tissue that they touch.

Consider that bullet travels through many different types of medium in a human body: bones, fluids, air space, elastic and inelastic tissues. The order in which the bullet encounters these different mediums is going to have a lot of influence on what the bullet does. While we can create some impressive looking numbers by doing some math with the velocity, diameter, and mass of the projectile we have completely ignored the variables of what it is we are shooting at. People are not made of uniform ballistic gelatin, and are highly resistant to damage in the short term.

Gelatin Studies and real world performance.

The shooting press and ammunition manufacturers talk a lot about gelatin studies and how they relate to defensive shooting. Greg Hamilton weighs in on the topic:

The main problem with the gelatin studies is that gelatin only is calibrated for pig muscle for depth of penetration. Not anything else. We can assume human muscle and pig muscle are similar enough that the is basically the same. After that all bets are off. The biggest problem is we shoot people in the chests, chests are mostly NOT muscle tissue. The measurements where the FBI came up with the magic 12-14″ are of the chest to transverse the goodies.

I wouldn’t shoot people with more than a 55 HP unless I was also trying to solve some other problem like distance at the same time.

Even though the street data is horribly collected, it is still data, and the best performers as “stoppers” on the street have been rounds that penetrate 8-10″ of ballistic gelatin. The FBI set 12-14 as a magic number and then went on to find rounds that go 12-14″ of muscle not 12-14″ of chest, which is the target they are concerned with getting through.

The 5.56 round with best real world results in the USA is a 55 HP, but in gelatin tests it only goes 10″ at most, yet it produces more “1 shot stops” than anything out there. Because it doesn’t penetrate far enough in gelatin people are discarding it but it has the highest DRT rate.

I wouldn’t shoot people with more than a 55 HP unless I was also trying to solve some other problem like distance at the same time.

Use of force on behalf of a third party.

Some of the most heated debates we have in classes is in regard our doctrine about not getting involved on the behalf of unknown third parties. I figured I would expand upon this a little bit, and better explain our position on this.

First of all InSights, teaches people to defend themselves and the people they care about not just from physical confrontations, but also from the legal penalties involved with the of force. Not getting involved in someone else’s dispute protects the individual from all of the risk of physical injury, criminal charges, and civil damages. Beyond calling the police, this is our default position. Staying out of other people’s problems will not protect the individual from feelings of guilt because they felt that they could have done something to help, or improve the general safety and welfare of larger society.

Frequently there are a lot of unknowns in any third party situation. Can we be sure of who is the aggressor and who is the victim? Can we be sure that the “innocents” are in fact innocent? We are contemplating putting an awful lot at risk (our lives, our freedom, our financial resources and those of our families) for a situation that if we had more information we might not feel compelled to get involved in. If I am sitting in prison for a mistake that I made (with the best of intentions) on be half of a stranger then who is going to protect and take care of the people I care about?

While the default is to call the police and otherwise stay out of it, it is up to the individual to make their choices and decide how much risk they are willing to assume on the behalf of a person unknown to them. Having a wider range of capabilities (in terms of tactics, skill, and equipment) allows one to mitigate some of this risk. I would say that it would I need a pretty clear picture of events before I would consider using deadly force on behalf of someone unknown to me.

9mm vs. .40 vs. .45

A student recently asked about the terminal ballistics of different handgun calibers and the effectiveness of different bullet types.

From John Holschen:

Get a gun/cartridge combination that goes bang every time you pull the trigger and which you can shoot quickly and accurately.

Get a gun/cartridge combination that goes bang every time you pull the trigger and which you can shoot quickly and accurately. No common defensive handgun cartridge will quickly and reliably stop a human being who is committed to causing serious bodily harm, unless the bullet from that cartridge is applied to the correct anatomy. When the bullet is applied to the correct anatomy ANY of the 3 will serve equally well (9mm, .40, .45).

Handgun projectiles don’t have enough “energy” to damage tissue other than the tissue they directly touch (the drill bit analogy.) Therefore whether they come out the other side (energy remaining) or stop in the body (all energy transferred to the target) doesn’t really change the wound dynamics. In fact you could make an argument that passing all the way through the body gives you the best chance of damaging more tissue. Of course this could present a hazard to any innocents behind and beyond the threat (and to the shooter in legal liability.)

A good quality hollow point handgun bullet will expand and therefore create a bigger hole. If that hole is in the brain the larger size may not matter much at all (I’ve dropped fairly large animals in their tracks with single 22LR head shot.) When the hole is in the pump (heart) or pipes (blood vessels) the larger hole will usually result in greater leakage per unit of time (given the placement is identical.) How much faster leakage, and does it matter? Who knows?

Also hollow points often have fairly sharp “petals” when expanded. There is a chance these will cut vessels that round nosed bullets sometimes push out of the way and leave intact. If you can get hollow points use them, if you can’t then you have to use what you have.