Got an email which is another aspect of the problem I wrote about recently. The author was asking that we get more fine-grained in our data, by making measurements of barrel lengths by one-eighth and one-quarter inch increments. Here’s a couple of relevant excerpts:
what more is really needed, is barrel lengths between 1-7/8 and 4-1/2″.
because of the proliferation of CCW and pocket pistols, and unresolved
questions about short barrel lengths that go all over between 2 and 3.75″,
and snubby revolvers that may be even shorter.
* * *
with that amount of precision, not only would you have data covering all
lengths of short barrels, but you could fabricate mathematical curves that
would predict velocities for any possible barrel length, metric or
otherwise, given the particular ammo.
It’s not an unreasonable thought, on the surface. Our data clearly shows that the largest gains in bullet velocity always come in length increases of very short barrels for all cartridges/calibers. So why not document the changes between, say, a 4.48″ barrel and a 4.01″ one? That’s the actual difference between a Glock 17 and a Glock 19, both very popular guns which are in 9mm. Or between a S&W Model 60 with a 2.125″ barrel and a S&W Model 360PD with a 1.875″ barrel?
Ideally, it’d be great to know whether that half or quarter inch difference was really worth it, when taking into consideration all the other factors in choosing a personal defense handgun.
The problem is that there are just too many different variables which factor into trying to get really reliable information on that scale.
Oh, if we wanted to, we could do these kinds of tests, and come up with some precise numbers, and publish those numbers. But it would be the illusion of precision, not actually useful data. That’s because of the limits of what we can accurately measure and trust, as well as the normal variations which occur in the manufacturing process … of the guns tested; of the ammunition used; of the chronograph doing the measurements; even, yes, changes in ambient temperature and barometric pressure.
That’s because while modern manufacturing is generally very, very good, nothing is perfect. Changes in tolerance in making barrels can lead to variation from one gun to the next. Changes in tolerance in measuring the amount of gunpowder which goes into each cartridge (as well as how tight the crimp is, or even tweaks in making the gunpowder itself) mean that no two batches of ammunition are exactly alike. And variations in making chronographs — from the sensors used, to slight differences in positioning, to glitches in the software which operate them — mean that your chronograph and mine might not agree on even the velocity of a bullet they both measure.
All of those little variations add up. Sometimes they will compound a problem in measuring. Sometimes they will cancel one another out. But there’s no way to know which it is.
This is why we’ve always said to consider our data as being indicative, not definitive. Use it to get a general idea of where your given choice of firearm will perform in terms of bullet velocity. Take a look at general performance you can expect from a brand or line of ammunition. Compare how this or that particular cartridge/caliber does versus another one you are considering.
But keep in mind that there’s no one perfect combination. You’re always going to be trading off a bunch of different factors in choosing a self-defense tool.
And never, ever forget that what matters most — FAR AND ABOVE your choice of gun or ammunition — is whether or not you can use your firearm accurately and reliably when you need to. Practice and training matters much more than whether or not you get an extra 25, or 100, or even 500 fps velocity out of whatever bullet is traveling downrange. Because if you can’t reliably hit your target under stress, no amount of muzzle energy is going to do you a damn bit of good.
If you want more information about how accuracy and precision can be problematic, this Wikipedia entry is a good place to start.
First, I want to share a couple of things I discovered in getting the Boberg out of the box, taken apart, and cleaned. This wasn’t strictly necessary, of course, because it came from the factory properly cleaned and lubed. But I’m very much a hands-on learner, and wanted to see what I was dealing with.
The gun is very user-friendly. To take it down for field stripping, you just rack the slide back, turn a lever, then move the slide forward. You don’t need any special tools, or an extra hand, or the strength of the pure. In that sense, it is very much in the modern design, as easy as a Glock. BUT without the need to dry-fire the gun first (which always makes me twitch, and may be the only thing I really dislike about the Glock design.)
Once the slide comes away from the frame, there are only 4 parts which come apart (other than the slide itself). There are no little fiddly bits to get lost or to spring out of sight when you’re not looking. You don’t have to disassemble the gun in a paper bag so that you don’t lose anything. It’s easy, obvious, and once you’ve done it following the owner’s manual, I doubt you’ll ever need to refer to the manual again. You can’t ask for more than that.
So, dis-assembly, cleaning, and re-assembly is all a breeze. Nice!
Having done so, I went through my box of misc. holsters to see what the Boberg might fit into. Because the XR45 is so new there are damned few holster-makers out there who have a holster listed to fit it. And I discovered something VERY interesting: the slide has almost the exact same dimensions as the Glock 21 (and similar Glock models). I first found this out in trying it in this little plastic holster: Glock Sport Combat Holster. I got out my calipers and did some measuring, and found that there was less than a millimeter difference in the width of the slide on the Glock 21 and the Boberg. They also have very similar profiles. And if you measure from the deepest pocket on the backstrap of either gun (where the web of your hand settles in) to the front of the trigger guard, there is less than 2 millimeters difference. Meaning that the Boberg fits almost perfectly into an open-muzzle holster for a Glock 21. Good to know!
OK, so what about going out shooting with the Boberg today?
Overall, I was very happy with how it performed on a first outing. I had a couple of minor glitches with improper feeding and ejection, but I am going to hold off on making any decisions about that until I give it at least another range session to break in. It does seem to fling spent cases somewhere into the next county, and I’m going to have to get used to that since I like to recover those cases and reload them. My very mild reloads wouldn’t cycle properly (the ones I took out are *really* mild), so I learned to take somewhat hotter loads. And the trigger is really l o n g … longer than either J-frame I own, and about like the little DAO Rohrbaugh I have. The gun seems to shoot a little to the left for me, but I won’t adjust the sights until I’m more familiar with it. Even so, I was able to consistently ding a 6″ spinner at 10 yards, which is all I expect from a pocket pistol.
How did it handle the different ammos I tried? Quite well, all in all.
I took my Glock 21 (5″ barrel) along for comparison, and shot over a single chronograph. Here are the average numbers:
Glock 21 Boberg
CorBon DPX 185gr +P 1060FPS 1030FPS
Winchester SXZ Training 230gr 850FPS 795FPS
Speer GDHP 230gr 840FPS 760FPS
CorBon JHP 230gr +P 980FPS 900FPS
The CorBon ammo is in line with what we tested formally. So that was good to see.
All together, I put about 100 rounds through the Boberg this afternoon, and wasn’t experiencing any real soreness or tiredness from all that shooting, which is unusual for such a small gun and full power loads. And just for comparison, I shot my .38Sp J-frame with 158gr LSWCHP +P from Buffalo Bore, which is my preferred SD loading for that gun, and the recoil was worse than with the Boberg. That’s for a ME comparison of 386 ft/lbs for the J-frame to 436 ft/labs for the Boberg with the 185gr CorBon loading.
So, that’s that. Already, the Boberg is equal to the J-frame, in my eyes. I shoot it as well. It has the same, or greater, amount of power. Reloading is faster. And it holds 6+1 to start. I still want to put it through its paces before I trust it as a carry gun, and there will be times when I still prefer to have the revolver, but already I can see that the Boberg is going to be a very nice addition to my collection.
More to come.
I’ve written about the innovative Boberg Arms XR9 previously. Here’s the take-away from my review:
This gun is a winner. It is well designed, and well made. The innovative design makes your brain hurt when you first see it. But the recoil is nothing like what you get from any other “pocket gun”, even when shooting full +P defensive ammunition. Usually with a pocket gun, you trade off the pain of shooting it a lot for the convenience of being able to carry it easily. With the Boberg, you don’t have to make that trade-off. I honestly wouldn’t be bothered at all by running a couple hundred rounds through this gun at the range.
Well, guess what followed me home today.
No, not an XR9. Something a little … bigger:
Yup, one of the new XR45s.
Here’s a pic of one from my outing with the other BBTI guys a few weeks ago:
It’s a little hard to tell how big the gun is in that pic. Here it is with some others:
Here’s the Boberg back to back with the Steyr:
With the EMP:
And with the J-frame:
And just for grins, here’s the Boberg with the J-frame sitting right on top of it:
Yeah, the 6+1 Boberg is actually smaller than the three other compact pistols. And it has a longer barrel than all three — 3.75″ on the Boberg, compared to 3.5″ in the Steyr, 3.0″ in the EMP, and 1.875″ on the J-frame.
How does it do this? Because of the innovative … some would say just plain weird … way the feed mechanism works. For the best explanation, take a look at the animation on the Boberg homepage, but basically as the slide comes back, it grabs a new cartridge out of the magazine by the rim and then positions it into the chamber. Yeah, you put the bullets in the magazine nose first. Like this:
And here’s a detail of the top of the loaded mag:
It takes some getting used to, I admit.
Now, while the Boberg is actually smaller in overall size than the other guns, it still has some heft to it: 22 ounces, as opposed to both the Steyr and the EMP at 26. The J-frame shown is a Model M&P 360 with the Scandium frame, so it comes in under 14 ounces. All of those are unloaded weight.
How does it shoot? Like this:
“Not bad at all.”
That was with .45 ACP+P high-end self-defense rounds.
Since I just got mine, it will take a while to find out all the little quirks that it has. But based on shooting one a few weeks ago, and in a much longer session with the 9mm version, I have little doubt that I will be very pleased with it. I’ve already poked around my selection of holsters, and found that the XR45 fits perfectly into a little belt slide holster I have for my Glock 21 Gen 4, as well as into a Mika Pocket Holster I use for the J-frame.
Last weekend I had the chance to revisit a couple of old friends, and try out something new: pump rifles. These guys:
If you check those links, you’ll see that I have written formal reviews for both the Uberti and the USFA previously. So I won’t spend much time talking about them.
But the little Taurus deserves a quick review. Because I found it to be a *very* nice little pump gun. The action was slick and didn’t have any problems, even though it was basically brand new. The Buckhorn sights are classic for a reason: they’re intuitive and work very well at modest distances. And even though the gun is relatively lightweight (compare the neck of the stock to the other two pump rifles above), there’s more than enough mass there to tame the recoil from the .22magnum cartridge. That means that you can get very quick and tight groups out of it even just standing and shooting it unsupported. Shooting it is just a blast, though one which doesn’t come with a lot of muzzle flash.
And the wood & finish on this gun is surprisingly good:
I also want to share a couple of detail pics of the engraving on the USFA:
And the other side:
I *do* like pump guns.
Some weeks back I put up a post about my preliminary experiences with a .460 Rowland conversion for my Glock 21 Gen 4. In it I mentioned how much I like the resultant gun, but also how I was having some problems with magazine wear when shooting full-force .460 loads.
Well, after thinking a lot more about it, as well as discussing it with people online and with the other BBTI members when they were here for the recent tests (one of whom has been a Glock armorer for 15+ years) a couple different strategies emerged for me to test. Briefly, those were:
- See whether putting in a heavier mag spring would help
- See whether the problem was due to the case length of the .460 Rowland cartridges (they’re 1/16″ longer than .45 ACP).
- See whether the problem was due to the *power* of the cartridges rather than the length of the cases.
To test the first, it was a simple matter to get a more powerful mag spring and test it in one of the magazines. I picked up a Wolff magazine spring from Midway and did so.
To test whether it was the simple case length of the .460 Rowland cases, I made up some .460 Rowland rounds using .45 ACP reloading standards.
To test whether it was the *power* of the .460 loads but not the case length was another matter. Here’s where we get to the Don’t Try This At Home part of today’s blog post: I made up a number of .45 ACP rounds which were loaded to .460 Rowland specs.
Let me repeat that again: Don’t Try This At Home. These are wildcat rounds, and potentially dangerous. Shooting them in a gun not rated for .460 Rowland stresses could very well result in catastrophic failure of your gun, of the “KABOOM!” variety. Even shooting them in a gun designed to handle .460 Rowland power was risky, since the .45 ACP cases do not have the same strength as the .460 Rowland cases. I made up just 10 rounds of each of these loadings, and was careful to make sure I shot them all, so that they didn’t accidentally wind up in a .45 not strong enough to take the punishment.
Here are each of the loadings I made up, just for reference, along with their approximate chrono results:
- 185gr XTP bullet, .45 ACP case, .460 Rowland power 1480fps
- 200gr RNFP bullet, .45 ACP case, .460 Rowland power 1440fps
- 230gr RNFP bullet, .45 ACP case, .460 Rowland power 1350fps
- 250gr LFN bullet, .45 ACP case, .460 Rowland power 1250fps
- 230gr RNFP bullet, .45 ACP case, .45 ACP power 920fps
- 230gr RNFP bullet, .460 Rowland case, .45 ACP power 925fps
- 185gr XTP bullet, .460 Rowland case, .460 Rowland power 1490fps
- 200gr RNFP bullet, .460 Rowland case, .460 Rowland power 1420fps
- 230gr RNFP bullet, .460 Rowland case, .460 Rowland power 1355fps
- 250gr LFN bullet, .460 Rowland case, .460 Rowland power 1265fps
No, I’m not going to give the specific powder amounts for any of those. I used Hodgdon Longshot powder, and you can look up the specs if you want to know more.
In addition, I had these factory loads on hand for comparison, along with their approximate chrono results:
11. 185gr DPX .45 ACP +P 1110fps
12. 230gr GDHP .45 ACP 850fps
13. 230gr JHP .45 ACP +P1040fps
14. 230gr JHP .460 Rowland 1380fps
15. 255gr LFN .460 Rowland1260fps
OK, a couple of comments before I go further: those are “approximate” chrono readings because I wasn’t being anywhere near as careful as we are when we do formal BBTI testing. To wit: I was just using one chrono; I wasn’t worried about getting the exact same number of readings (so long as I got three or four, I wasn’t too worried about it); and I didn’t do anything to control for consistent lighting or suchlike. But they should all be in the right ballpark.
So, looking over all those, you will see what I see: that there was a remarkable consistency in power levels, whether you’re looking at my reloads or factory loads, and between those rounds which used either .45 ACP cases or .460 Rowland cases. That tells me that following the published data for .460 Rowland reloads, and making some intelligent decisions on how to adapt those to the .45 ACP cases for purposes of this experiment, was by and large successful. Meaning that I can use those loads to fairly evaluate what makes a difference on the basic problem I was investigating: what is causing the magazine damage and how to resolve it.
So, what conclusions did I draw from all this?
First, the more powerful magazine spring seemed to help with consistent loading. I will be swapping out all the Glock 21 mag springs I have. This makes intuitive sense, since the slide is moving faster when shooting the more powerful rounds.
That doing a little customizing on the magazines also seems to help a great deal. Here’s a pic showing an unaltered magazine and one I have taken a Dremel tool to:
Note that these are just the magazine ‘boxes’ — the guts (spring, follower, etc) have all been removed for clarity.
With the altered magazine and stronger spring, any problems I had with Failure To Feed was minimized.
And most important, it is the *power* of the round, not the case length, which seems to cause damage to the unaltered magazines. Shooting the .460 Rowland power loads in the .45 ACP cases demonstrated this. Conversely, shooting the .45 ACP power loads in the .460 Rowland cases didn’t cause any magazine damage at all.
Two additional notes I want to add: the first is that I had pretty consistent problems with the heavy Lead Flat Nose rounds in all configurations. They kept getting jammed up in transitioning from the magazine into the chamber. I’ll probably continue to experiment with this in the future, but I’m not too worried about it, since many guns run into some ammo specific problems.
The second is that once again I was really impressed at just how well this reconfigured Glock 21 did with .45 ACP loads. Seriously, with the .460 Rowland conversion in place, there was very minimal recoil (more than a .22, but not much) and it was VERY easy to control and shoot the gun well. I suspect that going forward the vast majority of the shooting I will do with this will be using standard .45 ACP reloads, saving the much more powerful .460 Rowland rounds for occasional practice. In this sense, I am thinking of the .45/.460 relationship the way I think about .38/.357 — it seems to be a perfectly appropriate analogy.
Now that I have all this sorted, I can go ahead and write up a formal review. But I thought I would share a little of the process of how I got to this point.
I mentioned the other day that we are offering brass from the recent Cylinder Gap tests as a ‘premium’ thank-you for donations received.
Well, that info, as well as recognizing those who have made a donation to BBTI, are now listed on a new page for donations on the site. Of course, only those who wish to have their name listed do – others who prefer to remain anonymous can (and have) done so.
So far I’ve sent out 1,000 cases of .357 brass. I still have something like 1,100 of that cartridge remaining. And about 500 cases each of .38 Short, .38 Long Colt, and over 2,000 cases of .38 Special. I’d love to find homes for all of it.
Edited 2/3/2012 to add: Thanks for the response! All the once-shot brass has now been spoken for.
OK, as everyone knows, we’ve just put up a whole bunch of new data, most of which was generated during the early part of this past summer.
The bulk of that was generated during the Cylinder Gap tests, shooting .38 Shorts, .38 Longs, .38 Specials, and .357 Magnum rounds. And as a result we had two five-gallon buckets filled with spent brass.
Over the weekend I started doing some re-arranging of my reloading stuff, and it was time to tackle all that brass. I sorted it all. Then started cleaning it. So far I’ve run about 3000 .38 Special cases through the tumbler. And there’s a whole bunch (like 1600) .357 Magnum cases up next. Then the .38 Shorts and the Long Colt cases. This is more brass than I’d use in a couple of lifetimes (and I already have a couple thousand cases from previous tests and my general shooting).
So, here’s the deal: make a donation to BBTI, get some cleaned brass. Yup. For each $10.00, you get 100 cases of your choice (so long as supplies last, postage-paid in the US). This is all premium, brand-name brass, fired once. You can reload it. Or trade it. Or just keep it as proof of your support of our project. Frame it, for all I care.
So, help me out – take some of this brass off my hands.
*with apologies to Chrissie Hynde.
Nice graph and discussion about muzzle energy comparisons over barrel length using our data over on The Firing Line:
Full thread here: Light rounds in short barrels.
I think they did a good job with the photos they chose to go with my text:
One of my earliest memories is of shooting with my dad. I was about five or six. We were out at a relative’s place in the country. Plinkin’ cans with .22s. Then my dad let me shoot his service revolver for the first time, helping me hold up the Smith & Wesson Model 10 he had been issued by his department. Yeah, he was a cop.
Happy Father’s Day, everyone.
(Cross posted to the my personal blog.)
So, all last week we were finally conducting the Cylinder Gap tests. For this test alone, it was over 6,000 rounds. I thought as part of documenting the whole process I’d share a buttload of images and a brief description of each.
Given the size of this sequence of tests, we knew we needed to make a number of upgrades to our equipment and set-up. Jim Kasper did most of this work in advance. The Ransom Rest was mounted to a plywood platform which fit perfectly over one of the banquet tables, so we could just snap it into place each day.
To minimize problems with getting good readings from the chronographs, Jim K built a framework to support 250w lights which shined down into the sensor positions. After a couple of hours use, we decided to adapt a fabric panel from the new EZ Up we got to protect the chronos from weather as a diffuser.
Jim K also built a couple of racks to hold boxes of ammo. That way we didn’t have to sort and arrange everything each morning – just make sure the racks were filled before we left for the site each day, and then draw what was needed as we did the testing.
We had to run the generator continuously, so as to power the lights for the chronos. I designed a simple sound box out of 2″ construction insulation which would go together with a little duct tape, and would shield us from the excess noise while allowing the generator to operate.
The test platform was an Uberti Single Action Army clone in .38/.357. For other reference points, we also tested a number of ‘real world’ guns – shown here are a 2″ Chiappa .357, a 16″ Winchester 94 AE lever gun, a 4″ S&W 586, and a 3″ Bond Arms derringer. In addition we used a 1.875″ Ruger LCR in .38, a 1.875″ S&W 642, and a 6″ Python.
The Uberti worked remarkably well. We used a Ransom Rest in order to give consistent aiming and minimize hand trauma (when you’re going to shoot 6,000 rounds in the course of a week you’re going to suffer if you actually do it all by hand.)
Each day we’d take the lights, the chronographs, the guns, and the ammo home so as not to risk theft.
Our backdrop, same as with the previous tests, was a wall of railroad ties that is part of an old cabin. We used fresh-fallen Locust logs as a target, going through one or two 18″ logs a day, and replacing them as they got chewed up from so much shooting.
As we emptied boxes of ammunition, they got tossed under the tables, out of the way. All the cardboard was latter flattened and recycled. The plastic and styrofoam, unfortunately, was not. I must admit, as much as I like Buffalo Bore ammo, I hate their oversize boxes.
After we finished a round of shots, doing all of the ammunition with a set cylinder gap, we’d unscrew the barrel, change the shim (which changed the cylinder gap), and then did another round. With the Ransom Rest mounted in position, and the gun mounted in the Ransom Rest, there was an accumulation of gunpowder and particles from the cylinder gap. You can see this in the marks on the board under the gun, as well as the discoloration of the foam on the ‘blast shield’.
Here’s another shot which shows the gas/particle effect, with Jim Kasper in the background, a clipboard ready to record more of the chrono readings.
After we finished all the cylinder gap testing, we did the classic BBTI ‘chop tests’ on .223 Remington and .460 Rowland.
Even with the Ransom Rest, and using a Weaver Rail with a laser sight, it was easy to allow shots to creep up a little too high. In this case, the fabric used as a diffuser over the chronos served as a warning before we hit any of the lights.
7,000 rounds is a *lot*. Here’s a shot of a bucket about half filled with spent brass cartridges, taken towards the end of the testing. And this was the second of these 5-gallon cat litter pails used (the first was filled completely).
Testing the .223 Remington cartridge was the first real rifle round we’ve tested. The protocols we decided on were a bit different then in our previous chop tests of handgun cartridges. But we did go ahead and get down to a 3″ barrel, since we had a Bond Arms derringer in 3″ in that cartridge to test as a reference – this thing only has about a quarter-inch of rifling in the barrel. And it made a most impressive fireball when shot.
Just for giggles, we chopped the .223 barrel down to 2″, to show what would happen if you tried to go to that length. Here’s the result:
That should give a sense of what it was like this round of tests. I’ll have more to say about the testing, but thought it would be fun to share the images right away. We hope to have the data crunched and ready to post sometime later this month, but watch this blog for some previews.
My latest article is up on Guns.com. Here’s an excerpt:
I picked up the gun. Replaced my original magazine, the one with premium defensive ammunition. Chambered a round, took aim. Pulled the trigger.
Just a “click.”
I felt a cold chill run up my spine. My face felt a bit clammy. I waited, then cleared the magazine and round from the gun. My vision focused into a tight tunnel on the pistol in my hands, as the full implication of what had just happened settled in: my carry gun didn’t work when I expected it to.
Read the whole thing to find out what happened.
(Cross posted to my personal blog.)
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