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

Reprise: New Glock 21 Gen 4 .45 Review

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 3/6/2012. Images used are from that original article. Some additional observations at the end.

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Glocks are like King Arthur’s Excalibur in reverse: where Excalibur could only be drawn by the true King, Glocks are intended to be handguns that fit just about everyone. The reasons to own a Glock far outweigh reasons not to own one. However, as the company introduces more models under the Glock Gen 4 moniker, this year it’s coming out with three (Glock 21, 32 and 34), it may pull in the stragglers…

Glocks aren’t for Everyone

“Did you see that? He picked up the Glock. He secretly wants to shoot it.” Jim said, pointing and smiling at me. “It’s OK. We know you really want to give it a try.”

“One of us! One of us!” chanted Keith, who stood beside him.

“Yeah, OK, I’m curious,” I said, turning the new Glock over in my hand, examining it.

Keith laughed. “Just giving you some crap.”

The truth is, I was curious. I knew that Glock had changed a number of things about the gun with the introduction of the fourth Generation model (or Gen 4 as they call it), as with the rest of their line. I hadn’t gotten around to trying any of the new guns yet. But my friends knew my bias against Glocks.

Oh, I think Glock makes good guns. There’s little doubt of that in my mind. And they’ve had a profound effect on the modern firearms industry. But I just don’t like them.

To clarify, I don’t like shooting them. I’m just one of those people for whom the ergonomics of the Glock design doesn’t really work. It always feels like I’m holding a brick and trying to shoot it. They don’t point naturally, they don’t feel right in my hands, and I have a hard time hitting the broad side of a barn with one. A shame, really, since I do think that they’re good guns, incredibly reliable, and they’re reasonably priced with plenty of accessories available.

My friends knew this. But one of them had just gotten the new Glock 21 Gen 4, and wanted to give it a try. I wanted to see whether the modular back-strap system would change the feel of the gun at all in my hands.

Glock 21 Gen 4

The Glock 21 is a full-sized .45 ACP pistol, generally considered to be a ‘duty’ gun. It holds 13 rounds, has a 4.6-inch barrel, a full-sized grip, and weighs 26 ounces. All around, it is a quality gun, though the emphasis is on function rather than looks. The sights are good, the trigger decent, and the fit and finish up to par. You know what you’re going to get from a Glock.

Keith (who is a Glock-certified armorer for his police department) took the gun from me, quickly disassembled it while giving me a run-down on the changes of the Gen 4 model: a more aggressive grip texturing, larger (and reversible) magazine release, and the aforementioned back-strap system.

But the biggie was the redesigned recoil spring assembly, which has an inner and an outer spring (captured together). He held it up, said “this makes it the softest shooting .45 I’ve ever tried.”

Quickly reassembling it, we loaded up magazines and gave it a try.

Shooting

How was it? Well, keep in mind that, as I said, I don’t care for Glocks generally.

I have large hands, bigger than either of my friends’. But counter-intuitively, the smallest profile back-strap was the one that felt the best to me. The ergonomics were much the same as the older Glocks I had tried, but for whatever reason it was easier for me to accommodate the shape of the grip with the lower profile back-strap.

And yeah, the recoil was mild. Very mild. Even though we shot first target ball ammo, and then full +P self-defense rounds, it felt like my mild practice reloads out of a full-sized 1911. Between the different grip and the recoil, it was easy for me to hit the target with my first shot and with subsequent follow-up shots.

Final Thoughts: In Glock We Trust?

After I went through a couple of magazines, I could tell that the ergonomics were still not quite right for my hand – the recoil did tend to focus on an odd place at the base of my thumb. But for the first time I could actually see myself owning one of these guns.

I’m going to have to give some of the other Gen 4 models a try, see if they offer the same (or similar) shooting experience. I don’t mind having to change my mind about me and Glocks. Don’t mind at all.

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Well, I *did* get a G21 Gen4, and did a .460 Rowland conversion on it (more on that next time). And since then I’ve also added a G30S (which is also a .45) to my collection. So clearly I’ve decided that the Gen 4 Glocks are indeed suitable for me.

As I said above: they’re good guns. I don’t consider myself to be a ‘Glock Fanboy’, but I don’t hesitate to recommend them to people … with the caveat that you should *always* try shooting a gun (on multiple occasions, if possible) before buying. Even with a Gen 4 Glock.

 

Jim Downey

Dealing with power.

About 40 years ago, when I was an idiot teenager (yeah, I know — redundant, particularly in my case), we got this ’48 Willys Jeep. Since the engine was shot, we dropped an Olds V-6 in it. This was, essentially, like strapping a rocket to a skateboard. And it was too much power for idiot teenage me to handle.  Twice I snapped the driveshaft on the thing, just dumping the clutch too damned quickly. Twice. My uncle (who I lived with) was certain that I had been racing or something similar. The truth was, I didn’t even have that much of an excuse; I had simply goosed the engine too much and popped it into gear too fast. The original driveshaft just couldn’t handle that much of a power spike.

This is kinda what happens to your poor .45 ACP firearm when you decide to run some .45 Super through it.

With the Jeep, we wound up putting a more robust driveshaft in it. And I learned that if I wanted to keep driving it, I needed to be less of an idiot.

This analogy holds to how you should approach handling .45 Super power out of your .45 ACP gun. Chances are, very occasional use of these much more powerful loads won’t cause any problem in a quality, modern-made firearm. But if you’re smart, you’ll either greatly limit how many times you subject your gun (and your body) to that amount of power, or you will take steps to help manage it better and extend the life of your gun.

Typical ‘standard’ (non +P) .45 ACP loads tend to have a maximum pressure of between say 15,000 PSI and about 18,000 PSI. When you get past that, you get into ‘over-pressure’, or +P territory, up to about 23,000 PSI. This is the range most common modern firearms are built to handle safely.

But .45 Super generates more chamber pressure than that. How much more? Well, it’s a bit difficult to say, since there is a surprising dearth of data readily available. Neither my 49th Edition of Lyman’s Reloading Handbook nor my 13th Edition of Cartridges of the World have data for the .45 Super. Real Guns has some reloading formulas for .45 Super which give results consistent with our tests, but there are no pressure specs listed. Hodgdon Reloading has some pressure specs (in C.U.P.), but all their listed results for .45 Super are well below what our tests results were. Wikipedia lists .45 Super as having a maximum pressure of 28,000 PSI, and given that .460 Rowland is usually considered to run 35,000 – 40,000 PSI, that is probably in the correct ballpark.

I have written previously about converting a standard Glock 21 from .45 ACP over to .460 Rowland, and what is involved with that. Specifically, a new longer barrel with a fully-supported chamber which accommodates the longer case of the .460 Rowland, a 23 pound recoil spring, and a nice compensator to help tame the recoil. I also changed out the magazine springs, using an aftermarket product which increases the spring power by about 10%. This is because even with the other changes, the slide still moves much faster than with .45 ACP loads, and the increased mag spring power helps with reliability in feeding ammo. But even with all of that, shooting full-power .460 Rowland loads tends to cause damage to my magazines (as seen in the linked post).

Do you need to do all that in order for your firearm to handle frequent use of .45 Super loads? Well, I think that if you want to use a .460 Rowland conversion kit, it *will* tame the amount of recoil more than enough, but I don’t think that it is necessary to go quite that far. I should note that I have now run several hundred .45 Super loads through my Glock 21, and the gun has operated flawlessly — WITHOUT any damage to the magazines.

Converted G21 on left, G30S on right.

Rather, I think that the smart thing to do is to start off with going to a heavier recoil spring, perhaps swapping out a metal guide rod for a plastic one (if your gun comes with a plastic guide rod). Stronger magazine springs are probably still a good idea, to aid with reliable feeding. If suitable for your gun, add in a recoil buffer. These are the steps I have taken with my Glock 30S, and am planning for my Beretta Cx4 Storm. So far I have put a couple hundred .45 Super loads through the G30S with this configuration, and it has operated without a problem — again without any damage to the magazines.

As I said in my previous blog post, I still think that the .460 Rowland is a hell of a cartridge. But I think that the .45 Super offers almost as many advantages to the average shooter, with less hassle. I would still recommend that anyone who intends on shooting more than the very occasional .45 Super loads out of their gun consider making some simple changes to handle the additional power and extend the life of their gun. Don’t be like the idiot teenage me; deal with the power intelligently.

 

Jim Downey

 

 

Does primer size make a difference?

Following the success of our .45 Super/.450 SMC tests this summer, I sat down to work up some reloads which would mimic the factory ammo we had tested.

Since both of these cartridges are fairly unknown, there isn’t a whole lot of good information out there to draw upon. But there is some, at least for the .45 Super, and late last year/earlier this year I had worked up some preliminary loads, starting with .45 ACP +P (overpressure) published load data. But that was done using .460 Rowland cases and shot through my converted Glock G21, which I knew could handle the extra power. When reloading, it pays to be careful and conservative.

After I had seen the results from the extensive .45 Super/.450 SMC tests (some of which has already been published), I had a pretty good idea of where the power band for these loads was, and how different guns could handle it. Since I had previously worked up loads for .460 Rowland as well as done a lot of .45 ACP reloading over the years, I figured that I could come up with some pretty reasonable load levels to match what we had seen in the factory ammo.

So I sat down, looked through all my results and what was available elsewhere, and came up with loads* for three different bullet weights I had on hand: 185gr XTP, and 200gr & 230gr FP. I chose to use Longshot powder, which I have used successfully for both .45 ACP and .460 Rowland loads. (This is not an endorsement of any of these products, and I have not been compensated from these manufacturers in any way. This is just stuff I have on hand and know has worked previously.) I loaded 50 rounds each in .45 Super cases, using standard Large Pistol Primers.

But as I was doing so, I also realized that I had a bunch of .450 SMC cases left from the tests. And I figured that it might be an interesting experiment to load those cases to the exact same specs, other than the difference in primer size. To give the cartridge the benefit of better ignition, I used Small Magnum Pistol primers.  Again, I loaded 50 rounds of each bullet weight.

Again, other than the difference in primers, the reloads I worked up were identical.

 

OK, before I go any further, I want to toss in some caveats and explanations:

1. This was an informal test, using only one chronograph and under less rigorous conditions than the formal BBTI tests. It was just me shooting a string of five shots, keeping mental track of what the numbers were for each, and then writing down a ballpark figure which seemed to best represent the overall performance. Also, I wasn’t using the BBTI light-frame which gives us more consistent chrono results.
2. I was using my personal firearms, two of which (the Cx4 and Glock G30S) were brand new — this was their very first trip to the range. Yeah, I got them after seeing how similar guns performed in the .45 Super/.450 SMC tests earlier.

 

Now, about the guns used:

• Glock G30S with a Lone Wolf 23lb recoil spring and steel guide rod package. 3.77″ barrel
• Glock 21 converted to .460 Rowland (heavier recoil spring, compensator, and Lone Wolf .460 R barrel). 5.2″ barrel
• Beretta Cx4 carbine, standard right out of the case. But I am going to install a steel guide rod and heavy buffer in it. 16.6″ barrel

 

Results:

Ammo                                     G30S                                    G21                                             Cx4

.45 Super 185gr                 1185 fps / 577 ft-lbs                1250 fps/ 642  ft-lbs             1550 fps / 987 ft-lbs

.450 SMC 185gr                 1125 fps / 520 ft-lbs                1200 fps / 592 ft-lbs             1500 fps / 925 ft-lbs

 

.45 Super 200gr                1130 fps / 567 ft-lbs                1225 fps / 667 ft-lbs              1420 fps / 896 ft-lbs

.450 SMC 200gr                1090 fps  / 528 ft-lbs               1180 fps / 619 ft-lbs              1420 fps / 896 ft-lbs

 

.45 Super 230gr                1080 fps / 596 ft-lbs                 1160 fps / 687 ft-lbs              1310 fps / 877 ft-lbs

.450 SMC 230gr                1060 fps  / 676 ft-lbs                1130 fps / 652 ft-lbs              1310 fps / 877 ft-lbs

 

Interesting, eh? What seems to be happening is that full ignition of the powder takes longer with the .450 SMC loads. That would explain why there’s more of a discrepancy with the lighter bullets and shorter barrels, so the bullet clears the barrel faster — some of the powder hasn’t yet ignited with the Small Magnum Primer. But with the heavier bullets and longer barrel of the Cx4, there more time for more of the powder to ignite, reducing or eliminating the difference in performance.

That’s my take on it. If you have another one, please comment.

Also, I want to note just how well I managed to emulate the performance of the factory ammo. Compare the numbers above with what I have already published for the Glock 21 and Cx4 used in the tests earlier. And it isn’t published yet, but the G30S numbers are also right on-the-money for how the G36 used in the tests earlier performed (the two guns have the same barrel length). In all instances, my reloads* performed within 10-15 fps of the factory loads.

 

Jim Downey

*So, what exactly were those loads specs? OK, here’s the data, but provided with the understanding that you should WORK UP YOUR OWN LOADS starting below these amounts, and accepting that you do so on your own responsibility. Also note that any changes in bullet weight, bullet brand, or powder type may/will alter the results you can expect. AGAIN: you use this data on your own responsibility. Be safe.

All bullet weights had a 1.250″ O.A.L.

All were given a slight taper crimp.

185gr XTP rounds had 11.0gr of Longshot powder.

200gr FP rounds had 10.5gr of Longshot powder.

230gr FP rounds had 10.0gr of Longshot powder.