Session 5: Physics & Physiology: Defensive Ammunition

Shooting that you should plan on doing, is multiple rounds delivered quickly into the high center chest. And we want those rounds to have a certain minimum performance level in terms of power and energy. Transfer and damage. Transfer that energy to create damage inside of the human anatomy. The FBI does a better job of quantifying potential for damage out of, especially, handgun bullets than any other entity that I am aware of on the planet.

They do some very exhaustive tests and they do very controlled tests. So when you... I've done them. I do the demos. I do the tests.

I do the gelatin. The gelatin tests that are done, something called ballistic gelatin, it's just a special formula of density of this semi clear gelatin that you fire a bullet into and you make measurements. You know, how big did the bullet get? How much weight did the bullet retain? How deep did the bullet penetrate?

All those kinds of things. 90% of the ones that you'll see in the magazines, and you see at demonstrations at trade show events and gun shows, and out at the range during a defensive shooting class, are not controlled well enough to really mean as much as some people think they mean. And that's because 1% of density can dramatically affect what you're measuring. The temperature of the gelatin. You'll see most of the time when it's done in a quality way, the gelatin comes right out of at least a cooler, if not a refrigerated area, and is put on the slab and it's shot pretty quickly before the gelatin starts to soften up as it warms up.

So if your gelatin has been sitting out there for 20 minutes, while some guys telling you about the latest, greatest bullet design he's about to test, that gelatin is now different from the standard that he mixed it to and chilled it to. The FBI, doesn't do that. FBI is like, that's what they do, right? They're like accountants with badges, right? Like very specific, right?

So these guys they're like the meat thermometers in there, and like, okay, go! You know, they're like, they want them... It needs to be standardized. What do they do? Because they know agencies and us, and all over the world.

People are relying on that data to be accurate. So they make sure it's very accurate. And basically what's been determined is that with the with the right controls, what we're looking for is 12 to 15 inches of penetration. So if that's 12 inches, here's 15, 18. If the bullet gets to this area, through whatever you're shooting through, we'll get to that part in a minute.

If the bullet gets into that 12 to 15 inch area, in ballistic gelatin, that represents reaching the vitals in the human chest. That represents getting to the stuff we wanna get to. And in fact getting through it. That's what we want. We wanna pass through that tube, that is the center of the chest, and 12 to 15 inches of gelatin is what has been determined is perfect.

That's what we want. Now, one might say, "Well, 18 inches is even better." But unless you have like an extra heart hanging out on a in a backpack, then it's not better. Like 12 to 15 inches, that's what we're looking for. 18 inches of penetration inside the human body is not better by definition, right? 27 inches of penetration through ballistic gelatin is not three times as good.

That's not the way it works. All right? What we're looking for is the minimal amount of energy necessary... The minimal amount of power necessary to get to that 12 to 15 inches. Why?

Why do we want minimal amount of energy? If I'm shooting a 500 Magnum handgun that is capable of 42 inches of penetration through ballistic gelatin, there's a lot of recoil. There's a lot of energy. My follow-up shots are gonna be kind of slow. The gun's probably pretty heavy and big and massive, and it probably doesn't hold that many bullets.

If I'm getting 14 inches of penetration, instead of 42 inches of penetration, I'm reaching that minimum threshold of depth of penetration of energy. If I'm meeting minimum threshold, that probably means my gun doesn't have to be as heavy. I can hold more bullets. I can shoot them faster, because I'm dealing with less recoil. So, I want to be as efficient as possible.

Talk about this a lot when it comes to the physics and the physiology, and our techniques and our gear selection. How do I achieve my goal with the minimum amount of time, effort or energy expended? Well, I wanna achieve my depth of penetration goal with the minimum amount of recoil management. I wanna have as little weight as possible in that gun so I can carry it around all day and still manage recoil. I want to have as little in the bullets as possible.

I want the bullets to be as small as possible, to be able to do this, so that I can carry a whole bunch of them inside of that gun and in the extra magazines and on my body when I'm walking around. Because this penetration, this depth of penetration is gonna be a factor of a couple of things. It's gonna be the power in general, right? But that's weight and speed. There's mass and acceleration going on here.

That we have to factor both of those in. Because you could have something that's really light, moving really fast and it could get there. You could have something that's really moving slower. That just kind of momentum it's way crushing stuff to get there. Do that a couple different ways.

So what's the best balance? What's the best balance of light and fast, heavy and slow, reaching 12 to 15 inches, but not 42 inches but always going at least 12, not eight sometimes? Overwhelmingly, the science in 2013, says that the modern bonded core nine millimeter hollow point rounds. Basically the top of the line ammunition in any brand's configuration, the bonded core. That means the jacket and the core of the bullet are bonded together in nine millimeter, is going to be capable of reaching the 12 to 15 inch penetration mark in ballistic gelatin through the most likely intermediate barriers.

Because that's an important part of these tests that the FBI and others do. Is that they shoot through stuff, 'cause you rarely get attacked by naked people. So people with light or heavy clothing, right? Like this, like I'm dressed right now is light clothing. Put a leather jacket on or a thick winter wool coat with insulation.

That's heavy clothing. Those are the two things you need to worry about for personal defense. Inside of law enforcement, construction material, glass, maybe car parts, there's other things you may need to shoot through in a law enforcement capacity. And that changes some of this, but for personal defense, intermediate barriers, clothing. People very rarely attack other people on the other side of doors and cars and glass and all the other stuff.

That's not counter ambush, dynamic, critical incident personal defense shooting. So the intermediate barriers of light or heavy clothing, getting 12 to 15 inches of penetration, reaching the vitals in the high center chest as efficiently as we can. We end up looking at nine millimeter bonded, hollow points. That's what you're looking for. Now, the bonding is a heat process as part of the manufacturing.

And essentially, what you're looking at is there's a lead core. Something like that. There's your lead. And you've got a jacket around the lead, usually copper. You've got this jacket around the lead core.

Here's why that's important. The bonding of the jacket to the core. And this is why if you use old data, if you use older manufacturing technique, or not top of the line ammunition, you're going to find out that it says, no, in fact, you aren't gonna get reliable performance out of a nine millimeter. We need a bigger, heavier bullet. Well, one of the reasons was if you don't bond the jacket to the core, at the first hint of trouble, the intermediate barrier, quite often, the jacket strips off of the core.

So you've got this jacket floating around. It's very lightweight. And then you've got this core that is more or less deformed in one way or another, and might have some little fringy parts that are gonna break off. And you're gonna end up with inside of your ballistic gelatin, the jacket going to about here, and one piece of lead over here, and another piece of lead here, then another piece of lead here. Because once that jacket comes off, the uniformity of the expansion that you're looking at from that hallow point, and the weight retention, starts to degrade.

And that's why you don't really here. If you go look at some of the older style, gun reviews and ammunition reviews, and some of the magazines that are still done. There's some guys out there still doing them exactly the same way they were doing them in 1985. They buy a... They got a gun with a three and a half inch barrel meant for personal defense.

And they stick it in a thing called a ransom rest and they duct tape it down and they lock it, and they screw it to a cement table and they get a little robot finger to pull the trigger. And they tell you about what the three inch group with one brand of ammunition versus the 3.07 inch group with another brand of ammunition at 25 yards. As if that matters. Which it doesn't. Lemme assure you.

The ammunition grouping difference from a rest out of a three and a half inch barrel at 25 yards is probably one of the most useless pieces of information you'll ever be presented with in the gun industry. But that used to be the way people quantified what kind of ammo you should buy for your gun. Now, the reality is that 0.07 inches at 25 yards is largely irrelevant when it comes to your ability to control the gun in a dynamic critical incident at 10 feet. All right? So if the gun functions your ammunition reliably, it's an option.

As long as your gun functions it reliably, and then it's a bonded hollow point, don't worry about the 0.07 inches on that day with that guy's rested gun at 25 yards. Right? Which is something like what eight times the likely distance. Seven or eight times the likely distance you're gonna need to defend yourself. And you're not arrest, you're moving anyway.

You are breathing. You got deviation control from your human finger, not your robot finger, right? This stuff matters. The construction of the bullet matters. It doesn't matter if I'm gonna hit the guy here or here 0.7 inches away, right?

What matters is what's gonna happen when I get into his body? And when that jacket gets stripped, the lead is soft. Pieces of the lead may get torn off by the force of the human fleshy parts and bony parts hitting the lead or the lead hitting it, more specifically. So as the bullet tumbles and deforms and just kind of becomes a little clump of lead, oddly shaped maybe, you know, it's gonna be wider than it was but it's gonna be something crazy looking. So you get expansion from a hollow point.

But you don't get uniform expansion, you don't get weight retention. When you read those old reports about how hollow point ammunition, weight retention could be a big deal. You could see it might only have 82% of its initial weight. If you don't have the weight, you don't get the depth of penetration because that momentum weight retention is part of what helps penetrate. So if half of your...

Not a half, but if a third of your bullet is ripped off into little tiny lightweight particles that just barely penetrate, then that whatever's left, isn't gonna have the momentum to drive deep enough to hit the stuff you wanna hit, right? That's the concern. Well, when I have a bonded jacket, the jacket stays attached to the lead, and that makes both of those things perform the way they're intended to. Which is a mushrooming, a uniform expansion of that bullet so that you might've started out with a nine millimeter bullet, but now you've got a 10.8 millimeter bullet because you expanded and you added 20 or 30% of your distance, right? It might be even bigger than that.

11.8. Let's make it that. So you get this 20 to 30% expansion in size. That's the cone of damage, little tube of damage. You're cutting through the body.

You have a 199% weight retention. Hardly anything rips off or falls out or anything else. So you get more momentum. You get the depth of penetration you're looking for and you get more surface area from the bond at hollow point because of the retention and the uniform expansion. So I have more surface area, bigger hole and depth of penetration.

This is why today nine millimeter is a much more acceptable round than it was in 1982, because in 1982 this bonded core technology and the bullet design, the way the jacket was designed in the first place. You'll see that in many of the modern designs this jacket overlaps edges of the lead. So it actually contains the edges of the lead as opposed to stopping with an exposed semi jacketed hollow point that had lead bits that just got ripped off the front. Which is a very common bullet designed in the 70s and 80s. So modern defensive ammunition, makes the nine millimeter more viable as an option.

The good news is that if you have nine millimeter as an option, your magazines. Right? Because, when the research was done in the 80s, law enforcement decided, "Wow, nine millimeter bullets are no good. "We need something bigger. "And let's go back to the FBI." The FBI tried to use the 10 millimeter auto.

The bullet they designed to replace the nine millimeter. Not only was it one millimeter wider in diameter, but it was also a much powerful power charge behind it. So had a longer case as well. So you needed a bigger gun to hold it. But you could get more rounds into a 10 millimeter gun than you could into...

One of the other guns that was popular at the time was the 45 caliber, 1911 'cause 10 millimeter was smaller in diameter, about the same length. So you get more of these 10 millimeter rounds into a gun than you could 45. And you could get better penetration out of a 10 millimeter round in 1990 than you could out of a nine millimeter round. But it was too powerful. And what the FBI, who are really good at studying things found was that the average shooter really couldn't control the 10 millimeter round well enough to be able to get the hits fast enough to deliver the multiple rounds of the high center chest that they knew and we know now today also is what your goal is.

So if you can't shoot the gun fast enough and if the gun's grip has to be too big for the average human hand, especially, any of the smaller people that are a little below average. Now you're gonna issue them a gun that really doesn't fit their hand. It's a powerful gun. Too powerful. Because now your penetration is 22 inches.

Well, I don't need 22 inches. I only need 12 to 15 inches. So why do I have a bigger gun that's slower to shoot, harder to hold, with overkill in terms of power. Let's make that a little less powerful. So as you shave back the power in the 10 millimeter round, you end up with less and less powder.

So maybe we started out up here, now we're down to here, to get it controllable. When I've got this big gun shooting a not powerful round, let's make the guns smaller. Let's make the case smaller. Let's make everything a little bit smaller except the diameter. And what we end up with is the 40 Smith and Wesson round.

The 40 Smith and Wesson round is just a short 10 millimeter auto. And that was the answer for law enforcement. The answer for law enforcement was you want a heavier bullet that moves a little bit slower than a 10 millimeter, but gives us the depth of penetration we need in a nine millimeter size gun. Now, today, there's still an argument for the 40 caliber in law enforcement, because of these intermediate barriers. Because if I have to shoot through car glass, which I do as a cop, if I have to shoot through doors which I do as a cop, if I occasionally have to actually shoot through the metal parts of the vehicle which I do occasionally as a cop.

Remember plausibility principle? It's more plausible, it is more reasonable, to expect to have to shoot through heavy intermediate barriers if I am a police officer with flashy red and blue lights and the shiny badge, and I'm going towards the bad guy. It is not nearly as reasonable to expect that you're gonna need that in the personal defense realm. So knowing that, let's go back to these magazines. Two magazines of about equal size, artistic license.

If I can carry nine millimeter rounds and get that many of them, or I can carry 40 caliber rounds and only have that many of them, what's the better deal? Well, I already said I wanted to shoot multiple rounds into the high center chest. So the more rounds I can carry in any given package, better. These are relatively high pressure rounds that are generally gonna be noticeably heavier than a nine millimeter, which means more recoil. More recoil, means it takes more time, effort energy to control the gun.

If I have to control the gun to put more time, effort, energy, controlling the gun, I'm firing my shot slower. As many rounds as I need into the high center chest, and as short a time as possible. Less recoil, less time between rounds is better. So again, we're back to efficiency, achieving my goal with as little time, effort or energy as possible. And that's why when it comes to the physics of bullet selection, we tell people nine millimeter.

We know where we wanna hit. We aren't counting on a single shot stopping the bad guy. We're gonna figure. We're gonna fire multiple shots. Overwhelmingly, we see multiple shots required when it comes to physiological stops.

So the faster I can shoot multiple rounds into the bad guy's chest, getting my defensively accurate shot, the better off I am as long as I'm meeting this minimum threshold. Four reasons we recommend the nine millimeter. One, it meets the minimum threshold. Two, it's the lowest power round that allows me to meet the minimum threshold. Which means I can shoot it faster than other rounds that will meet the minimum threshold.

We have higher capacity in any given package than other rounds that will meet the minimum threshold. And the fourth one is it's cheaper. Cheaper to shoot nine millimeter. You get more practice out of your nine millimeter gun than you do out of your 40 or 45 or your 357 SIG round. which is actually also nine millimeters in diameter but it's a much more powerful round, 'cause it uses the 40 caliber case.

And you can get lost in the weeds really quick with bullet performance and the physics of anatomy or damage against the human anatomy, and how that physics works. That's why we try to simplify it. But if you're going to get into how to choose the best gear for your counter ambush approach to defensive shooting, you've got to remember a couple of things we talked about earlier. I can't predict how many rounds it's gonna take to stop the next threat. I can't even predict how many threats are gonna be involved in my next dynamic critical incident or when it's gonna happen.

The more bullets I have that will meet the minimum threshold, the better prepared I am.