Shooting big stuff.

Ever hear of a 4 Bore?

Here’s the first line from the Wikipedia entry:

Four bore or 4 bore is an almost obsolete black powder caliber of the 19th century, used for the hunting of large and potentially dangerous game animals.

The term “4 Bore” indicated that it would fire a sphere of lead weighing 4 ounces, or one-quarter of a pound of lead. This was an old measurement system from which we also get our shotgun gauge measurements: a 12 gauge shoots a sphere of 1/12th a pound of lead, etc. So, a 4 Bore shoots a sphere of lead that is three times the weight of what a 12 gauge would shoot. As in a ball 1.052″ diameter that weighs 4 ounces, or 1,750gr. Compare that to a typical 12 gauge slug, which weighs from one to 1.125 ounces. The 4 Bore ball is more than three times the weight.

And shooting one feels like it.

Well, depending on the black powder load, of course.

Here’s the one we shot, the Blunderbuss on the right:

And here’s looking down the muzzle:

As the maker of the gun notes:

This 4 bore Blunderbuss can be pretty intimidating when you’re looking down the end of one.

Especially when the end is TWO inches in diameter and the bore is more than one inch too!

The thought of shooting it was pretty intimidating, too.

The maker recommends a load of just 100gr of Fg black powder. So that’s what we started with. Here’s what that looked like, being shot by Jim K of the BBTI team:

Not bad, right? Yeah, it felt like shooting a typical 12 gauge loaded with slugs. Of course, the Blunderbuss doesn’t have a modern firearm design, with no mechanism to reduce recoil.

And here’s my friend Roger shooting it with the recommended load, in slow motion:

Now, Roger’s a big guy. Over 6’6″. And like all of us who shot the 4 Bore, he has decades of experience shooting all manner of long guns, from mild black powder muskets to modern heavy magnums. Now just watch what happens when we increased the load in the 4 Bore to 200gr of Fg black powder:

And here’s Keith of the BBTI team shooting the 4 Bore with that full 200gr load:

Impressive, eh? I don’t have video of my shooting it, but I do have the bruises to prove I did.

Well, now, think about this: historically, these guns were loaded with up to 500gr of black powder. Bloody hell.

OK, let’s talk ballistics.

See the orange thing in the foreground in most of the video? That’s a LabRadar ‘chronograph’. It said we got about 500 fps from the ‘light’ loads, and about 700 fps out of the ‘heavy’ loads. That would give us a muzzle energy of about 970 and 1900 foot-pounds, respectively.

Your typical 12 gauge slug has a ME of about 2600 ft/lbs.

So, what gives? Why does the 4 Bore look (and feel) like it had so much more power?

I’ve been thinking about this for the last several days, and I think the answer is that a heavier bullet gives you more perceived recoil.

I’ve discussed this previously: Velocity is great, but mass penetrates. In that post, I used the example of a whiffle-ball versus a baseball, where they both had the same “ME”, but where you’d feel a significant difference if you were hit by both.

And I think that the same thing is happening here. For what it’s worth, you’d need to push the 4 Bore ball to about 800 fps to get it to the same nominal ME as a 12 gauge shotgun slug. To get to *triple* the ME of a 12 gauge shotgun slug, you’d need to push the 4 Bore ball to about 1400 fps. My guess is that the historical 500gr load of black powder might accomplish that.

But I sure as hell wouldn’t want to shoot it.

Oh, and how accurate was the 4 Bore? Here’s our target from the full-power loads:

Not bad for no sights, at about 15 yards. And look at the size of those holes!

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OK, let’s talk about the other gun in the pic at the top. It’s a Hand Mortar, designed to throw a small hand grenade further than the human arm could. We had this one just for a little fun, shooting tennis balls about 100 yards using 70gr of Fg black powder. Like this:

Here’s a slow motion version of my friend Tim shooting it:

And here’s another of my friend Charles:

Black powder is so much fun!

Jim Downey

Handgun caliber and lethality.

This post is NOT about gun control, even though the article which it references specifically is. I don’t want to get into that discussion here, and will delete any comments which attempt to discuss it.

Rather, I want to look at the article in order to better understand ‘real world’ handgun effectiveness, in terms of the article’s conclusions. Specifically, as relates to the correlation between handgun power (what they call ‘caliber’) and lethality.

First, I want to note that the article assumes that there is a direct relationship between caliber and power, but the terminology used to distinguish between small, medium, and large caliber firearms is imprecise and potentially misleading. Here are the classifications from the beginning of the article:

These 367 cases were divided into 3 groups by caliber: small (.22, .25, and .32), medium (.38, .380, and 9 mm), or large (.357 magnum, .40, .44 magnum, .45, 10 mm, and 7.62 × 39 mm).

And then again later:

In all analyses, caliber was coded as either small (.22, .25, and .32), medium (.38, .380, and 9 mm), or large (.357 magnum, .40, .44 magnum, .45, 10 mm, and 7.62 × 39 mm).

OK, obviously, what they actually mean are cartridges, not calibers. That’s because while there is a real difference in average power between .38 Special, .380 ACP, 9mm, and .357 Magnum cartridges, all four are nominally the same caliber (.355 – .357). The case dimensions, and the amount/type of gunpowder in it, makes a very big difference in the amount of power (muzzle energy) generated.

So suppose that what they actually mean is that the amount of power generated by a given cartridge correlates to the lethality of the handgun in practical use. Because otherwise, you’d have to include the .357 Magnum data with the “medium” calibers. Does that make sense?

Well, intuitively, it does. I think most experienced firearms users would agree that in general, a more powerful gun is more effective for self defense (or for offense, which this study is about). Other things being equal (ability to shoot either cartridge well and accurately, concealability, etc), most of us would rather have a .38 Sp/9mm over a .22. But when you start looking at the range of what they call “medium” and “large” calibers, things aren’t nearly so clear. To borrow from a previous post, this graph shows that the muzzle energies between 9mm+P, .40 S&W, and .45 ACP are almost identical in our testing:

 

Note that 10mm (and .357 Sig) are another step up in power, and that .357 Mag out of a longer barrel outperforms all of them. This graph doesn’t show it, but .38 Sp is very similar to 9mm, .45 Super is as good as or better than .357 Mag, and .44 Magnum beats everything.

So, what to make of all this? This claim:

Relative to shootings involving small-caliber firearms (reference category), the odds of death if the gun was large caliber were 4.5 times higher (OR, 4.54; 95% CI, 2.37-8.70; P < .001) and, if medium caliber, 2.3 times higher (OR, 2.25; 95% CI, 1.37-3.70; P = .001).

certainly seems to carry a lot of import, but I’m just not sure how much to trust it. My statistical skills are not up to critiquing their analysis or offering my own assessment using their data in any rigorous way. Perhaps someone else can do so.

I suspect that what we actually see here is that there is a continuum over a range of different handgun powers and lethality which includes a number of different factors, but which the study tried to simplify using artificial distinctions for their own purposes.

Which basically takes us back to what gun owners have known and argued about for decades: there are just too many factors to say that a given cartridge/caliber is better than another in some ideal sense, and that each person has to find the right balance which makes sense for themselves in a given context. For some situations, you want a bigger bullet. For other situations, you want a smaller gun. And for most situations, you want what you prefer.

 

Jim Downey

 

Reprise: Is Muzzle Energy Really a Measure of Handgun Effectiveness?

Prompted by my friends over at the Liberal Gun Club, this is another 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 2/13/2012. Some additional observations at the end.

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Would you rather be shot with a modern, Jacketed Hollow Point bullet from a .32 ACP or have someone throw a baseball at you? Seems like a silly question, doesn’t it? But did you know that the ‘muzzle energy’ of the two is about the same? Seriously, it is and that’s just one reason why trying to use muzzle energy as a measurement of handgun effectiveness is problematic.

Calculating Muzzle Energy

First off, what is ‘muzzle energy’ (ME)? Wikipedia has a pretty good description and discussion of it. Here’s the simple definition:

Muzzle energy is the kinetic energy of a bullet as it is expelled from the muzzle of a firearm. It is often used as a rough indication of the destructive potential of a given firearm or load. The heavier the bullet and the faster it moves, the higher its muzzle energy and the more damage it will do.

For those who are trying to remember your high school physics, kinetic energy is the energy (or power) of something moving. You can calculate kinetic energy using the classic formula:

E = 1/2mv^2

Which is just mathematic notation for “Energy equals one-half the mass of an object times the square of its velocity.”

Doing the actual calculations can be a bit of a pain, since you have to convert everything into consistent units, but the formula is there on the Wikipedia page (and can be found elsewhere) if you want to give it a go. Fortunately, there are a number of websites out there which will calculate muzzle energy for you – you just plug in the relevant numbers and out comes the result. We also have muzzle energy graphs for all the calibers/ammunition tested at BBTI.

Batter up?

If you go through and check all the muzzle energy numbers for handguns with a 6″ or less barrel which we’ve tested (BBTI that is), in .22, .25. or .32, you’ll see that all except one (and you’ll have to go to the site to see which one it is) comes in under 111 foot-pounds.

Why did I choose that number? Because that would be the kinetic energy of a baseball thrown at 100 mph. Check my numbers: a standard baseball weighs 5.25 ounces, which is about 2,315 grains. 100 mph is about 147 fps. That means the kinetic energy of a baseball thrown at 100 mph is 111 ft-lbs.

Now, we’re not all pro baseball pitchers. And I really wouldn’t want to just stand there and let someone throw a baseball at me. But I would much rather risk a broken bone or a concussion over the damage that even a small caliber handgun would do.

The Trouble with Muzzle Energy

And therein lies the problem with using muzzle energy as the defining standard to measure effectiveness: it doesn’t really tell you anything about penetration. A baseball is large enough that even in the hands of Justin Verlander it’s not going to penetrate my chest and poke a hole in my heart or some other vital organ. If I catch one to the head, it may well break facial bones or even crack my skull, but I’d have a pretty good chance of surviving it.

Now, I think muzzle energy is a useful measure of how much power a given handgun has. That’s why we have it available for all the testing we’ve done on BBTI. But it is just one tool, and has to be taken into consideration with other relevant measures in order to decide the effectiveness of a given gun or caliber/cartridge. Like measures such as depth of penetration. And temporary and permanent wound channels. And accuracy in the hands of the shooter. And ease of follow-up shots. And ease of carry.

I’ve seen any number of schemes people have come up with to try and quantify all the different factors so that you can objectively determine the “best” handgun for self defense. Some are interesting, but I think they all miss the point that it is an inherently subjective matter, where each individual has to weigh their own different needs and abilities.

Sure, muzzle energy is a factor to consider. But I think the old adage of “location (where a bullet hits) is king, and penetration is queen” sums it up nicely.

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In the five years since I wrote that, my thinking has evolved somewhat. Well, perhaps it is better to say that it has ‘expanded’. I still agree with everything above, but I’m now even more inclined to go with a relatively heavy bullet for penetration over impressive ME numbers. I think that comes from shooting a number of different brands of ammo where the manufacturer has chosen to go with a very fast, but very light bullet to get an amazing ME, with the argument that this is more likely to cause some kind of terminal shock, citing tests showing significant ‘temporary wound channels’ and such in ballistic gel.

But you really can’t cheat physics. If you dump a lot of kinetic energy very quickly into creating a temporary wound channel, then you have less energy for other things. Like penetration. Or bullet expansion. And those are factors which are considered important in how well a handgun bullet performs in stopping an attacker. That’s why the seminal FBI research paper on the topic says this:

Kinetic energy does not wound. Temporary cavity does not wound. The much discussed “shock” of bullet impact is a fable and “knock down” power is a myth. The critical element is penetration. The bullet must pass through the large, blood bearing organs and be of sufficient diameter to promote rapid bleeding. Penetration less than 12 inches is too little, and, in the words of two of the participants in the1987 Wound Ballistics Workshop, “too little penetration will get you killed.” Given desirable and reliable penetration, the only way to increase bullet effectiveness is to increase the severity of the wound by increasing the size of hole made by the bullet. Any bullet which will not penetrate through vital organs from less than optimal angles is not acceptable. Of those that will penetrate, the edge is always with the bigger bullet.

 

Now, you can still argue over the relative merits of the size of the bullet, and whether a 9mm or a .45 is more effective. You can argue about trade-offs between recoil & round count. About this or that bullet design. Those are all completely valid factors to consider from everything I have seen and learned about ballistics, and there’s plenty of room for debate.

But me, I want to make sure that at the very minimum, the defensive ammo I carry will 1) penetrate and 2) expand reliably when shot out of my gun. And if you can’t demonstrate that in ballistic gel tests, I don’t care how impressive the velocity of the ammo is or how big the temporary wound cavity is.

So I’ll stick with my ‘standard for caliber’ weight bullets, thanks. Now, if I can drive those faster and still maintain control of my defensive gun, then I will do so. Because, yeah, some Muzzle Energy curves are better than others.

 

Jim Downey

Comparison shopping.

Remember this graph comparing Muzzle Energy (ME)?

 

Well, a discussion elsewhere got me to thinking …

So, let’s take a look at .45 Super:

 

See what I see? Yeah, at 3″ and 4″ all the .45 Super loads are superior in terms of ME over all the other cartridges in the top graph. At 5″ the .357 Mag catches up with some of the .45 Super loads, and at 6″ it is in the center of the pack.

To really do the comparison right, I’d need to average all the .45 Super loads, then add them directly to the first graph, but that’s more time and trouble than I want to take. But my point is that of all the ‘conventional’ CCW-caliber/size guns, it looks like the .45 Super is at the top of the pile. We did formal testing of just one .460 Rowland, and it is comparable to the .45 Super at those barrel lengths (though I know from informal testing that some other loads are more powerful). You have to step up to full .44 Mag to beat either the .357 Mag or .45 Super.

Interesting.

Jim Downey

Velocity is great, but mass penetrates.

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.

OK then.

Now let’s go look at our most recent .45 ACP tests. And in particular, the Muzzle Energy graph for those tests:

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.

Jim Downey

.45 Super data now published.

At long last, we’ve now put up the page with the results of our .45 Super/.450 SMC tests earlier this year! We’ve also published the additional .45 ACP rounds tested at the same time, which doubles the amount of data for that cartridge available on our site.

As noted on the new .45 Super page:

.45 Super and .450 SMC (Short Magnum Cartridge) are two relatively recent variations on the classic .45 ACP cartridge.  They were designed to gain more power from the cartridge than it was originally designed to produce, using modern smokeless powder and more robust case specifications.  And these rounds achieve this goal, producing about 100% greater muzzle energy for a given bullet weight over standard pressure .45 ACP rounds, and about a 50% increase over .45 ACP +P (over-pressure) rounds.

Take a look at the Muzzle Energy graph for .45 Super:

One thing I notice right away is that in general, the energy curve for this cartridge is much more pronounced and consistent than the energy curve for .45 ACP loads (whether standard pressure or +P). In other words, this is a round which continues to see impressive gains in energy over a longer barrel length, rather than flattening out starting at 8 – 10″. That’s more like the behavior you see from a magnum revolver round. Even the .460 Rowland tends to not see much gain after about 10″ — with the result that while the .460 Rowland is clearly a superior round for shorter barrels over the .45 Super, most loadings of the .45 Super meet or exceed the energy of the .460 Rowland by the time you get to carbine-length barrels. And you don’t need to rechamber your gun to shoot it.

Seeing this performance out of the Cx4 Storm actually prompted me to act on something I had just been thinking about: to go out and buy one of the remaining new Cx4 Storms out there (Beretta decided to discontinue the gun in that caliber earlier this year). In a future blog post I’ll talk about the alterations I am making to that gun, and that I have made to a Glock G30S, to handle the additional power of the .45 Super cartridge.

For now, enjoy playing with the data. And please be sure to share it with others! Because while I have long been an advocate for the .460 Rowland — a cartridge I still like very much — I now think that the .45 Super is a better choice for most people. Further discussion of that next time.

 

Jim Downey