My friends over at the Liberal Gun Club asked if they could have my BBTI blog entries cross-posted on their site. This is the second in an occasional series of revisiting some of my old articles which had been published elsewhere over the years, perhaps lightly edited or updated with my current thoughts on the topic discussed. This is an article I wrote for Guns.com, and it originally ran 2/16/2011. Some additional observations at the end.
You need to choose self-defense ammunition for your gun. Simple, right? Just get the biggest, the baddest, the most powerful ammunition in the correct caliber for your gun, and you’re set, right?
Wrong. Wrong, on so many levels. For a whole bunch of reasons. We’ll get to that.
Shooters have earned the reputation as an opinionated breed and arguments over ammunition are a staple of firearms discussions, and have been for at least the last couple of decades. Much of this stems from the fact that every week it seems, you’ll see “fresh” claims from manufacturers touting this new bullet design or that new improvement to the gunpowder purportedly to maximize power or minimize flash. And the truth is there have been a lot of improvements to ammunition in recent years, but, if you don’t cut through the hype you can easily find yourself over-emphasizing the importance of featured improvement in any given ammunition.
Perhaps it’s best to consider it by way of example. While the basic hollowpoint design has been around since the 19th century, I remember when simple wadcutters or ball ammunition was about all that was available for most handguns. Cagey folks would sometimes score the front of a wadcutter with a knife (sometimes in a precarious manner—please don’t do this Taxi Driver-style with live ammunition) to help it ‘open up’ on impact. Jacketed soft point ammunition was considered “high tech” and thus distrusted. And yet, these simple bullets stopped a lot of attacks, killed a lot of people and saved a lot of lives.
I’m not saying that you don’t want good, modern, self-defense ammunition. You probably do. I sure as hell do. I want a bullet designed to open up to maximum size and still penetrate properly at the velocity expected when using it. If you are ever in a situation where you need to use a firearm for self-defense, you want it to be as effective as possible in stopping a threat, as quickly as possible.
Modern firearms are not magic wands. They are not science-fiction zap guns. How they work is they cause a small piece of metal to impact a body with a variable amount of force. That small piece of metal can cause more or less damage, depending on what it hits and how hard, and how the bullet behaves. Here’s the key that a lot of people forget: as a general rule, location trumps power. All you have to do is meditate on the fact that a miss with a .44 magnum is nowhere near as effective as a hit with a .25 ACP. And when I say “a miss” I’m talking about any shot which does not hit the central nervous system, a major organ, or a main blood vessel (and even then it matters exactly which of these are hit, and how). Plenty of people have recovered from being shot multiple times with a .45. Plenty of people have been killed by a well-placed .22 round.
Hitting your target is what is most important and for most of us that is harder to do with over-powered ammunition we’re not used to shooting regularly. Chances are that under the stress of an actual encounter, your first shot may not be effective at stopping an attack. That means follow-up shots will be needed, and you’d better be able to do so accurately. If you can’t get back on target because of extreme recoil, then what’s the point of all that extra power? If you can’t get back on target because you’ve been blinded by the flash of extra powder burning after it leaves the muzzle, well hell, that’s not good either.
Nestled up alongside power is having an ammunition that will actually work well in your gun. Some guns are notoriously ammunition sensitive and you don’t want to just be finding out your gun doesn’t particularly care for an ammo when you really need it to go boom. Check with others (friends or online forums) who have your type of gun, and see what ammo works for them. Then test it yourself, in your actual gun. Some people won’t carry a particular ammunition until they have run a couple of hundred rounds of that ammunition through their gun. Personally, I’ll run a box or two through the gun and consider that sufficient; you’ll know after that if your gun generally handles that ammunition with any problems.
So, once you have an idea of what ammunition will work in your particular gun, how do you choose between brands? As I’ve previously discussed, you can’t necessarily trust manufacturer hype. So, how to judge?
Well, you can do some research online. The fellows at The Box of Truth have done a lot of informal testing of ammunition to see how different rounds penetrate and perform. The Brass Fetcher has done a lot of more formal testing using ballistic gelatin. Ballistics By The Inch (which is yours truly’s site) has a lot of data showing velocity for different ammunition. And most gun forums will have anecdotal testing done by members, which can provide a lot of insight.
But don’t over-think this. Handguns are handguns. Yeah, some are more powerful than others, but all are compromises – hitting your target is the single most important thing. And like I said, ammunition can help, but only to a certain extent. We’re talking marginal benefits, at best, whatever the manufacturers claim. So relax; all of the big name brands are probably adequate, and you’d be hard pressed to make a truly bad decision, so long as the ammunition will function reliably in your gun and you can hit your target with it.
Of course, as you do more research, and get more experience, you’ll probably find you like some ammunition more than others, for whatever reason. That’s fine. It just means that you’re ready to join in the (generally genial) arguments over such matters with other firearms owners. Welcome to the club.
Some additional thoughts, six years later …
Bullet design has continued to improve, with new and occasionally odd-looking designs and materials being introduced regularly. Some of these are *really* interesting, but I keep coming back to the basic truth that the most important factor is hitting the target. No super-corkscrew-unobtanium bullet designed to penetrate all known barriers but still stop inside a bad guy is worth a damn if you miss hitting your target.
And that means practice (and training, if appropriate) is more important than hardware. What I, and a lot of shooters concerned about their self-defense skill, will do is to use practice ammo for training when they go to the range, to keep their basic skill set honed. And then supplement that with a magazine or two (or a cylinder or two) of their carry ammo, so they refresh their knowledge of how it feels and behaves in their gun. This can help keep practice costs down (since good SD ammo can be expensive), but also keeps carry ammo fresh.
OK, kiddies, it’s time for SCIENCE!
Ballistic science, specifically. I promise to keep the math to a minimum, because I don’t like it much, either. Jim Kasper is the one who thinks in terms of equations, not me.
If you look at any of the various pages for test results on BBTI you will see that each caliber/cartridge also has a link for a Muzzle Energy (the kinetic energy of a bullet as it leaves the muzzle of a gun) graph for that set of results. That’s because Muzzle Energy can also give an idea of the effectiveness of a given ammo, since it is a calculation of both the weight of a bullet as well as the velocity it is traveling. This calculation, specifically:
Here’s what that says in English, taken from the explanation that goes with that image on Wikipedia:
The kinetic energy is equal to 1/2 the product of the mass and the square of the speed.
In other words, you multiply the weight of the bullet times the square of the velocity, then take half of whatever number you get. And that gives you the Muzzle Energy, usually (as on our site) expressed in foot-pounds of energy.
So there are two ways you can change the result: change the amount of weight, or change the amount of velocity.
But since it is the square of the velocity (the velocity times itself), changes to the velocity have a larger impact on the final amount of Muzzle Energy. That’s the reason why how the velocity changes due to barrel length is such a big deal, and why we’ve done all the research that we’ve done over the last seven years.
But while Muzzle Energy gives you a good way to compare the power and potential effectiveness of a given cartridge as a self-defense round, there are a couple of other factors to consider. A couple of VERY important factors.
One is the shape and composition of the bullet itself. There’s a very good (surprisingly good, in fact — I heartily recommend you read the whole thing) discussion of the basic shapes and how they interact with the human body in this online teaching tool intended for medical students. The relevant excerpt:
Designing a bullet for efficient transfer of energy to a particular target is not straightforward, for targets differ. To penetrate the thick hide and tough bone of an elephant, the bullet must be pointed, of small diameter, and durable enough to resist disintegration. However, such a bullet would penetrate most human tissues like a spear, doing little more damage than a knife wound. A bullet designed to damage human tissues would need some sort of “brakes” so that all the KE was transmitted to the target.
It is easier to design features that aid deceleration of a larger, slower moving bullet in tissues than a small, high velocity bullet. Such measures include shape modifications like round (round nose), flattened (wadcutter), or cupped (hollowpoint) bullet nose. Round nose bullets provide the least braking, are usually jacketed, and are useful mostly in low velocity handguns. The wadcutter design provides the most braking from shape alone, is not jacketed, and is used in low velocity handguns (often for target practice). A semi-wadcutter design is intermediate between the round nose and wadcutter and is useful at medium velocity. Hollowpoint bullet design facilitates turning the bullet “inside out” and flattening the front, referred to as “expansion.” Expansion reliably occurs only at velocities exceeding 1200 fps, so is suited only to the highest velocity handguns.
Now, while that last bit about needing to exceed 1200 fps may have been true, or a ‘good enough’ approximation a few years ago, it isn’t entirely true today. There has been a significant improvement in bullet design in the last two decades (and these innovations continue at a rapid pace), so that there are now plenty of handgun loads available which will reliably expand as intended in the velocity range expected from the round.
The other REALLY important consideration in bullet effectiveness is penetration. This is so important, in fact, that it is the major criteria used by the FBI and others in assessing performance. From Wikipedia:
According to Dr. Martin Fackler and the International Wound Ballistics Association (IWBA), between 12.5 and 14 inches (318 and 356 mm) of penetration in calibrated tissue simulant is optimal performance for a bullet which is meant to be used defensively, against a human adversary. They also believe that penetration is one of the most important factors when choosing a bullet (and that the number one factor is shot placement). If the bullet penetrates less than their guidelines, it is inadequate, and if it penetrates more, it is still satisfactory though not optimal. The FBI’s penetration requirement is very similar at 12 to 18 inches (305 to 457 mm).
A penetration depth of 12.5 to 14 inches (318 and 356 mm) may seem excessive, but a bullet sheds velocity—and crushes a narrower hole—as it penetrates deeper, while losing velocity, so the bullet might be crushing a very small amount of tissue (simulating an “ice pick” injury) during its last two or three inches of travel, giving only between 9.5 and 12 inches of effective wide-area penetration.
As noted above, the design of the bullet can have a substantial effect on how well it penetrates. But another big factor is the weight, or mass, of the bullet relative to its cross-section — this is called ‘sectional density‘. Simply put, a bullet with a large cross-section and high mass will penetrate more than a bullet with the same cross-section but low mass moving at the same speed. It isn’t penetration, but think of how hard a baseball hits versus a whiffleball moving at the same speed. They’re basically the same size, but the mass is what makes a big difference. (See also ‘ballistic coefficient‘).
With me so far?
OK, let’s go all the way back up to the top where I discussed Muzzle Energy. See the equation? Right. Let’s use the baseball/whiffleball analogy again. Let’s say that the baseball weighs 5.0 ounces, which is 2,187.5 grains. And the whiffleball weighs 2/3 of an ounce, or 291.8 grains. A pitcher can throw either ball at say 60 mph, which is 88 fps. That means (using this calculator) that the Kinetic Energy of a baseball when it leaves the pitcher’s hand is 37 foot-pounds, and the whiffleball is just 5 foot-pounds. Got that?
But let’s say that because it is so light, the pitcher can throw the wiffleball twice as fast as he can throw a baseball. That now boosts the Kinetic Energy of the whiffleball to 20 foot-pounds.
And if you triple the velocity of the whiffleball? That gives it a Kinetic Energy of 45 foot-pounds. Yeah, more than the baseball traveling at 88 fps.
What is the top line on that graph? Yeah, Liberty Civil Defense +P 78 gr JHP. It has almost 861 foot-pounds of energy, which is more than any other round included in those tests. By the Muzzle Energy measure, this is clearly the superior round.
But would it penetrate enough?
Maybe. Brass Fetcher doesn’t list the Liberty Civil Defense +P 78 gr JHP. But they did test a 90 gr RBCD round, which penetrated to 12.0″ and only expanded by 0.269 square inch. Compare that to the other bullets listed on his page, and you’ll see that while the depth of penetration isn’t too bad when compared to other, heavier, bullets, that round is tied with one other for the least amount of expansion.
Driving a lightweight bullet much, much faster makes the Muzzle Energy look very impressive. Just the velocity of the Liberty Civil Defense +P 78 gr JHP is impressive — 1865 fps out of a 5″ barrel is at least 50% faster than any other round on our test results page, and almost 400 fps faster than even the hottest of the .45 Super loads tested.
But how well would it actually penetrate? Without formally testing it, we can’t say for sure. But I am skeptical. I’m not going to volunteer to getting shot with one of the things (or even hit with a whiffleball traveling 180 mph), but I’m also not going to rely on it to work as it has to in the real world, where deep penetration is critical. I want a bullet with enough punch to get through a light barrier, if necessary. Like this video from Hickok45, via The Firearm Blog:
Personally, I prefer a heavier bullet. Ideally, I want one which is also going to have a fair amount of velocity behind it (which is why I have adapted my .45s to handle the .45 Super). All things being equal (sectional density, bullet configuration and composition), velocity is great, but mass is what penetrates.
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