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: Converting a Glock 21 to .460 Rowland

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 9/18/2012. Images used are from that original article. Some additional observations at the end.

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At the risk of seeming to be obsessed with the .460 Rowland cartridge, given that I have written about it three times this year, allow me to give a report on what it is actually like to convert a Generation 3 Glock 21 over to .460 Rowland using a conversion kit from 460Rowland.com.

One of my Ballistics By The Inch buddies had a Glock 21 9/11 Commemorative model, and was anxious to try the conversion kit. He ordered it in, got it in good time, and we got together to give it a try.

The process

First thing we did was field strip the Glock and check everything over. The gun has been shot, but not a lot. Everything with it looked fine.

We went ahead and set up a single chrono, just so we could get some numbers for comparison. This wasn’t the usual more formal BBTI set-up, but we figured it would suffice.

Using the original .45 ACP hardware in the Glock, we shot some standard 230-grain ball ammo. It gave us readings in the expected range: about 780 fps. Then we ran some premium self-defense ammo, Cor-Bon 230 grain +P JHPs, and again got performance in the range expected: about 980 fps. Satisfied that the Glock was performing normally, we turned to the conversion kit.

The kit used came with just three items:

1. A new five-inch barrel chambered for the .460 Rowland and with about a half inch of threading on the end
2. A new captured recoil spring assembly
3. A threaded compensator

The current kit shown on the site now also has a small packet of what looks like blue loc-tite and runs for $319 (now $387, more for a Gen 4).

The instructions indicate that you’re supposed to secure the compensator with loc-tite, so my buddy brought some along. This is probably why they now include a small packet of it with the kit.

If you’re familiar with Glocks, you know that field-stripping the gun is simplicity itself. We did so, and removed the original spring assembly and barrel.

Then we checked to make sure the new parts looked like they would fit. Everything seemed fine in comparison to the original parts. We installed the new barrel, then the new recoil spring assembly. Close examination seemed to indicate everything was where it needed to be.

We re-assembled the slide to the frame. Again, everything seemed to be fine. Manually cycling the gun, there was little or no noticeable difference.

We decided to go ahead and try the gun at that point, before mounting the compensator, just to get a feel for it. This is not recommended, but we wanted to be thorough in our test, as informal as it was.

The test

The .460 Rowland ammo we had was the same as we had tested previously for BBTI, and what started me on this kick: Cor-Bon 230 grain ‘Hunter’ JHP.

Initial shots were about 1170 fps. Just about what I expected. The recoil was stout, and there was some muzzle flip, but neither was particularly bad. We proceeded to mount the compensator that came with the kit. The compensator just screws onto the threaded portion of the extended barrel. You screw it down until it is almost to the front of the slide, with the compensation holes facing straight up. Then back it off a couple of turns, add some loc-tite, and reposition the compensator. Allow it to dry sufficiently.

Once it was ready (not completely cured, but sufficient for our needs), we loaded the gun again and ran it through its paces.

And we gained about 50 fps. Yeah, all the subsequent chronograph readings were 1220 to 1230. Nice.

Also nice was the way the compensator changed the character of the recoil: it was still stout, but there was significantly less muzzle flip. We all shot the gun through at least a full magazine (13 rounds) and agreed – it was faster and easier to re-acquire your target with the compensator, and the gun took less man-handling to control. The recoil was, as noted, still stout, and felt different than the slow push of shooting a .45 ACP out of the Glock. It was probably closer to shooting a 10mm.

The 460Rowland.com site touts a Nosler 185 grain JHP “carry ammo” and claims that it achieves 1550 fps. I haven’t tested it, but I’d believe it. And if so, you’re talking a whopping 987 foot-pounds of energy out of the thing. That puts it beyond the 10mm. Beyond the .41 Magnum. That puts you pretty solidly into .44 Magnum territory. Even the 230 grain round we tested has a respectable 766 foot-pounds of energy – compared to 526 for the same weight bullet out of a .45 ACP +P.

A little suggestion…

I said it before and I’ll repeat it here: if you carry a .45, you should instead be carrying a .460 Rowland.

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Oh, boy.

Time for a serving of Crow: I now seldom recommend that people make the full switch to .460 Rowland.

Why? As I said in a recent blog post:

As I have previously noted, I have now changed over to using the .45 Super cartridge rather than the .460 Rowland because the .45 Super offers most of the benefits of the .460 Rowland without some of the disadvantages. But I have kept the conversion kit in place because it gives me more flexibility in ammo selection and more control of the gun. And since I don’t carry the G21, the extra mass/length of the compensator doesn’t make a difference in day-to-day use.

So, yeah.

“Disadvantages” to the .460 Rowland? Well, I could never get my G21 to stop chewing up mags when shooting full-power .460 Rowland out of it. And the recoil could be … daunting, even for me (I’m not particularly recoil sensitive). I couldn’t ever share ammo with someone who had ‘just’ a .45 (the .460 case is slightly longer, and won’t chamber) — which is good (and intentional), because a lot of guns can’t handle the extra power of the .460 Rowland.

Now, the .460 Rowland definitely IS more powerful than the .45 Super out of handgun-length barrels. By a couple hundred foot-pounds of Muzzle Energy. That’s about the power difference of the .45 Super over the .45 ACP +P. But the .45 Super beats pretty much every other common handgun cartridge except the .460 Rowland and .44 Magnum.

You have to decide for yourself what trade-offs to make. But do so in an informed way. Look at the numbers. Try guns set up to shoot the different cartridges if at all possible — I often will stage my G21 to shoot three rounds each of .45 ACP, then .45 Super, then .460 Rowland so people can try the three rounds head-to-head. And usually they decide that .45 Super is more than sufficient.

 

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

Join the party.

All along, we’ve said that if someone wanted to take the time, trouble, and expense to do some additional research along the lines of our protocols, that we’d be happy to include their data on our site. This is particularly true if it helped expand the selection of “real world guns” associated with the data for a given caliber/cartridge. Well, for the first time someone has expressed an interest in doing just that, prompting us to come up with an outline of what standards we feel are required for making sure it relates to our previous tests.

The biggest problem is that ammo manufacturers may, and do, change the performance of their products from time to time. This is why we have on occasion revisited certain cartridges, doing full formal chop tests in order to check how specific lines of ammo have changed. That gives us a benchmark to compare other ammo after a period of several years have passed, and shows how new tests relate to the old data.

But without going to such an extent, how can we be reasonably sure that new data collected by others using their own firearms is useful in comparison to our published data?

After some discussion, we feel that so long as any new testing includes three or more of the specific types of ammo (same manufacturer, same bullet weight & design) we had tested previously, then that will give enough of a benchmark for fair comparison. (Obviously, in instances where we didn’t test that many different types of ammo in a given cartridge, adjustments would need to be made). With that in mind, here are the protocols we would require in order to include new data on our site (with full credit to the persons conducting the tests, of course):

1. Full description and images of the test platform (firearm) used in the tests. This must specify the make, model number, barrel length, and condition of the firearm. Ideally, it will also include the age of the firearm.
2. That a good commercial chronograph be used. Brand isn’t critical — there seems to be sufficient consistency between different models that this isn’t a concern. However, the brand and model should be noted.
3. Chronographs must be positioned approximately 15 feet in front of the muzzle of the firearm used to test the ammo. This is what we started with in our tests, and have maintained as our standard through all the tests.
4. That five or six data points be collected for each type of ammo tested. This can be done the way we did it, shooting three shots through two different chronographs, or by shooting six shots through one chronograph.
5. All data must be documented with images of the raw data sheets. Feel free to use the same template we used in our tests, or come up with your own.
6. Images of each actual box of ammo used in the test must be provided, which show the brand, caliber/cartridge, and bullet weight. Also including manufacturer’s lot number would be preferred, but isn’t always possible.
7. A note about weather conditions at the time of the test and approximate elevation of the test site above sea level should be included.

We hope that this will allow others to help contribute to our published data, while still maintaining confidence in the *value* of that data. Please, if you are interested in conducting your own tests, contact us in advance just so we can go over any questions.

 

Jim Downey