Ballistics by the inch

Reprise: Levering the Playing Field: a Magnum Opus

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, and it originally ran 3/26/2011. Some additional observations at the end.


In an earlier article, when I said you’d get about a 15% increase in bullet velocity when using a pistol caliber carbine over a handgun, I lied.

Or, rather, I was neglecting one particular class of pistol ammunition which can develop upwards of a 50% increase in velocity/power in a carbine over a handgun: the “magnums,” usually shot out of a lever-action gun. This would include .327 Federal Magnum, .357 Magnum, .41 Magnum, and .44 Magnum.

These cartridges are rimmed, initially developed as powerful handgun rounds, and have their origins in black powder cartridges. This history is important for understanding why they are different than most of the other pistol cartridges and the carbines that use them.

We’ll start with the .357 Magnum, the first of these cartridges developed.

Back in the 1930s a number of people, Elmer Keith most notable among them, were looking to improve the ballistic performance of the .38 Special cartridge. This had been a cartridge originally loaded with black powder. Black powder takes up a lot of space – typically two to four times as much space as smokeless powder of a similar power. Meaning that when people started loading .38 Special cartridges with smokeless powder, the cartridge was mostly empty.

Now, if you were looking to get more power out of a .38 Special, and you saw all that unused space in the cartridge, what would be the obvious thing to do? Right – add more smokeless powder.

The problem is, many of the handguns chambered for the .38 Special using black powder were not strong enough to handle .38 Special cartridges over-charged with smokeless powder. And having handguns blowing up is rough on the customers. Heavier-framed guns could handle the extra power, but how to distinguish between the different power levels and what cartridge was appropriate for which guns?

The solution was to come up with a cartridge, which was almost the same as the .38 Special, but would not chamber in the older guns because it was just a little bit longer. This was the .357 Magnum.

There are two important aspects of the cartridge as far as it applies to lever guns. One is just simply the ability to use more gunpowder (a typical gunpowder load for a .357 magnum uses about half again as much as used in a .38 Special.) And the other is that you can get more complete combustion of the gunpowder used, perhaps even use a much slower burning gunpowder. This means that the acceleration of the bullet continues for a longer period of time.

How much of a difference does this make? Well, from the BBTI data for the .357 Magnum, the Cor Bon 125gr JHP out of a 4″ barrel gives 1,496 fps – and 2,113 fps out of an 18″ barrel. Compare that to the .38 Special Cor Bon 125gr JHP out of a 4″ barrel at 996 fps and 1,190 fps out of an 18″ barrel. That’s a gain of 617 fps for the .357 Magnum and just 194 fps for the .38 Special. Put another way, you get over a 41% improvement with the Magnum and just 19% with the Special using the longer barrel.

Similar improvements can be seen with other loads in the .357 Magnum. And with the other magnum cartridges. And when you start getting any of these bullets up in the range of 1,500 – 2,000 fps, you’re hitting rifle cartridge velocity and power. The low end of rifle cartridge velocity and power, but nonetheless still very impressive.

There’s another advantage to these pistol caliber lever guns: flexibility. Let’s take that .357 again. On the high end of the power band, you can use it as a reliable deer-hunting gun without concern. But if you put some down-loaded .38 Special rounds in it, you can also use it to hunt rabbit or squirrel. I suppose you could even use snake/rat shot loads, though most folks don’t recommend those loads due to concerns over barrel damage. Shooting mild .38 Special loads makes for a great day just plinking at the range.

One thing that I consider a real shame: you can get good quality lever guns for the .357, the .41, and the .44 magnums. But to the best of my knowledge, no one yet makes a .327 Magnum lever gun. I would think that such a gun would meet with a lot of popularity – properly designed, it should be able to handle the .327 Federal Magnum cartridge, the .32 H&R cartridge, even the .32 S&W Long. Again, with the right powder loads, this would give the gun a great deal of flexibility for target shooting and hunting small to medium sized game/varmits.

So, if you like the idea of having a carbine in the same cartridge as your handgun, but want to be able to maximize the power available to you, think about a good lever gun. It was a good idea in the 19th century, and one that still makes a lot of sense today.


Some additional thoughts …

I’m still a little surprised that no manufacturer has come out with a production .327 mag lever gun, though occasionally you hear rumors that this company or that company is going to do so. But I must admit that as time has gone on I’ve grown less interested in the .327 cartridge, since firearms options are so limited — definitely a chicken & egg problem.

One very notable absence from the above discussion is the .22 WMR (.22 Magnum), for the simple reason that we hadn’t tested it yet when I wrote the article. You can find a later article about it here.

Something I didn’t address when I wrote the article initially was ammunition which was formulated to take greater advantage of the longer barrel of a lever gun. Several manufacturers produce such ammo, perhaps most notably Hornady and Buffalo Bore. A blog post which includes the latter ammo out of my 94 Winchester AE can be found here, with subsequent posts here and here.

And lastly, there’s another cartridge we tested which really should be included in the “magnum” category, because it sees the same increasing power levels out to at least 18″ of barrel: .45 Super. This proved to be more than a little surprising, since it is based on the .45 ACP cartridge.  Most semi-auto firearms which shoot the .45 ACP should be able to handle a limited amount of .45 Super, but if you want a lever gun set up to handle the cartridge you’ll have to get it from a gunsmith.


Jim Downey

April 2, 2017 Posted by | .22WMR, .32 H&R, .327 Federal Magnum, .357 Magnum, .38 Special, .41 Magnum, .44 Magnum, .45 ACP, .45 Super, .450 SMC, Data, Discussion. | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , | 3 Comments

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

September 9, 2016 Posted by | .22, .223, .22WMR, .25 ACP, .30 carbine, .32 ACP, .32 H&R, .327 Federal Magnum, .357 Magnum, .357 SIG, .38 Special, .380 ACP, .40 S&W, .41 Magnum, .44 Magnum, .44 Special, .45 ACP, .45 Colt, .45 Super, .450 SMC, .460 Rowland, 10mm, 9mm Luger (9x19), 9mm Mak, 9mm Ultra, Anecdotes, Data, Discussion., General Procedures | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , | Leave a comment

An absurd comparison. Or is it?

We had another of those wonderful & rare mid-50s January days here today, so I decided to get out for a little range time.

In addition to the other shooting I did (basically, practice with some of my preferred CCW guns), I also did a little head-to-head comparison between a Smith & Wesson M&P 360 J-frame in .38 Special and a Colt Anaconda in .44 Magnum.

Wait … what? Why on Earth would anyone even consider trying to do such an absurd comparison? The S&W is a very small gun, and weighs just 13.3 ounces. The Anaconda is a monster, weighing in at 53 ounces (with the 6″ barrel that mine has), and is literally twice as long and high as the J-frame. The .38 Special is generally considered a sufficient but low-power cartridge for self defense, while the .44 Magnum still holds a place in the popular mind as ‘the most powerful handgun in the world‘ (even though it isn’t).

Well, I was curious about the perceived recoil between the two, shooting my preferred loads for each. The topic had come up in chatting with a friend recently, and I thought I would do a little informal test, just to see what I thought.

So for the M&P 360 I shot the Buffalo Bore .38 special +P, 158 gr. LSWHC-GC which I have chrono’d out of this gun at 1050 fps, with a ME of 386 ft-lbs.

And for the Anaconda I shot Hornady .44 Remington Magnum 240gr XTP JHP, which I have chrono’d at 1376 fps, with a ME of 1009 ft-lbs. (Actually, I don’t have a ‘preferred carry ammo’ for this gun, but this is typical of what I shoot out of it. Were I going to use it as a bear-defense gun, I’d load it with this.)

My conclusion? That the M&P 360 was worse, in terms of perceived recoil. In fact, I’d say that it was *much* worse.

It’s completely subjective, but it does make sense, for a couple of reasons.

First, look at the weight of each gun, compared to the ME of the bullets shot. The J-frame is 13.3 ounces, or about 25% of the 53 ounce weight of the Anaconda. But the ME of 386 ft-lbs of the .38 Special bullet is 38.25% of the ME of the .44 Mag at 1009 ft-lbs. Put another way, the J-frame has to deal with 29 ft-lbs of energy per ounce of the gun, where the Anaconda has just 19 ft-lbs of energy per ounce of the gun. That’s a big difference.

Also, all that recoil of the J-frame is concentrated into a much smaller grip, when compared to the relatively large grip of the Anaconda. Simply, it the difference between being smacked with a hammer and a bag of sand, in terms of how it feels to your (or at least, my) hand.



Jim Downey

January 31, 2016 Posted by | .38 Special, .44 Magnum, Anecdotes, Discussion. | , , , , , , , , , , , , , , , , , | 4 Comments

The illusion of precision.

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.


Jim Downey

If you want more information about how accuracy and precision can be problematic, this Wikipedia entry is a good place to start.

September 6, 2015 Posted by | .357 Magnum, .38 Special, 9mm Luger (9x19), Data, Discussion., General Procedures | , , , , , , , , , , , , , , , , | 2 Comments

First date with the Boberg XR45-S

Over the weekend I posted about picking up my new Boberg XR45-S. This afternoon I took it out for a first “getting to know you” session. More about that in a moment.

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.

Jim Downey

December 8, 2014 Posted by | .38 Special, .45 ACP, Boberg Arms, Discussion., General Procedures | , , , , , , , , , , , , , , , | 4 Comments

Boberg XR45

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:

all 4

Starting in the upper left corner and going clockwise, those are: A Steyr S9 in 9mm, a Springfield EMP in 9mm, the Boberg XR45 in .45ACP, and a S&W J-frame in .38sp.

Here’s the Boberg back to back with the Steyr:

with S9

With the EMP:

with EMP

And with the J-frame:

with j-frame

And just for grins, here’s the Boberg with the J-frame sitting right on top of it:

on top

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:

with mag

And here’s a detail of the top of the loaded mag:

mag loaded

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.

Jim Downey

December 6, 2014 Posted by | .38 Special, .45 ACP, 9mm Luger (9x19) | , , , , , , , , , , , , , , , , , , , , , , | 7 Comments

Six shooter.

Well, well, well, BBTI made it to six years of shooting fun and research!

Yup, six years ago today we posted the first iteration of Ballistics By The Inch, and included data for 13 different handgun cartridges. Since then we’ve continued to expand on that original research, including some extensive testing on how much of an effect the cylinder gap on revolvers has, what performance differences you can expect from polygonal over traditional land & groove rifling, and added another 9 cartridges, as well as going back and including a very large selection of real world guns in all the different cartridges. This blog has had 100,000+ visitors and the BBTI site itself has had something like 25 – 30 million visits (the number is vague because of changes in hosting and record-keeping over time).

We’ve had an impact. I’ve seen incoming links from all around the world, in languages I didn’t even recognize. There’s probably not a single firearms discussion group/blog/site out there which hasn’t mentioned us at some point, and our data is regularly cited in discussions about the trade-offs you make in selecting one cartridge or barrel length over another. I’ve answered countless emails asking about specific points in our data, and have been warmly thanked in return for the work we’ve done. And on more than a few occasions people have pointed out corrections which need to be made, or offered suggestions on how we could improve the site, sometimes providing the results from their own crunching of our data.

When we started, it was fairly unusual to see much solid information on ammo boxes about how the ammunition performed in actual testing. Now that information is common, and expected. Manufacturer websites regularly specify real performance data along with what kind of gun was used for that testing. And the data provided has gotten a lot more … reliable, let’s say. We’ve been contacted by both ammo and firearms manufacturers, who have asked if they can link to our data to support their claims of performance — the answer is always “yes” so long as they make it clear that our data is public and not an endorsement of their product. And we’ve never taken a dime from any of those companies, so we can keep our data unbiased.

And we’re not done. We have specific plans in the works to test at least one more new cartridge (and possibly revisit an old favorite) in 2015. I try to regularly post to the blog additional informal research, as well as sharing some fun shooting and firearms trials/reviews. There’s already been one firearms-related patent issued to a member of the BBTI team, and we’ll likely see several more to come. Because we’re curious guys, and want to share our discoveries and ideas with the world.

So, onward and upward, as the saying goes. Thanks to all who have cited us, written about us, told their friends about us. Thanks to all who have taken the time to write with questions and suggestions. And thanks to all who have donated to help offset the ongoing costs of hosting and testing — it makes a difference, and is appreciated.


Jim Downey

November 28, 2014 Posted by | .22, .223, .22WMR, .25 ACP, .30 carbine, .32 ACP, .32 H&R, .327 Federal Magnum, .357 Magnum, .357 SIG, .38 Special, .380 ACP, .40 S&W, .41 Magnum, .44 Magnum, .44 Special, .45 ACP, .45 Colt, .460 Rowland, 10mm, 6.5 Swedish, 9mm Luger (9x19), 9mm Mak, 9mm Ultra, Anecdotes, Data, Discussion., General Procedures, Links, Shotgun ballistics | , , , , , , , , , , , , , , , , , , , , , | 1 Comment

Pump it up.

Last weekend I had the chance to revisit a couple of old friends, and try out something new: pump rifles. These guys:

PumpsFrom top to bottom:


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:

Taurus pump


I also want to share a couple of detail pics of the engraving on the USFA:


And the other side:


Very nice!

I *do* like pump guns.


Jim Downey


November 22, 2014 Posted by | .22WMR, .357 Magnum, .38 Special, .45 Colt | , , , , , , , , , , , , , , , | Leave a comment

Perceived recoil and bullet weight.

Got a great question recently, and I thought I would share some of my thoughts about it, then invite others to weigh in. Here’s the question:

I hope that you folks can help me with a question I have had for many years now. Why is the recoil so much heavier with lighter bullets in the same caliber and powder loadings than heavier bullets of the same caliber and loadings?

For example. With my S&W model 60, Gold Dot L/E 38 special 135 grain JHP +P loads recoil much harder than the Remington 125 grain JHP +P loads. The same thing happens with my Glock mod 23 .40cal when I shoot 180 grain JHP rounds vs 165 grain JHP rounds. The 165 grain rounds recoil much harder. One would think the heavier round with the same powder load would recoil harder. Can you help?

Perceived recoil is a surprisingly complex problem. It’s not just a matter of total force, but the ‘shape’ of the recoil impulse as well. Then there are the ergonomics of how a particular gun fits a particular person/hand. Add in the mechanical action of how the gun operates (some use part of the recoil energy to cycle the action, some don’t), and various psychological/physiological factors (are you tired? just had an adrenaline dump? afraid of a given gun/caliber/cartridge?), and you can see how many different factors might come into play.

A good place to start is to look at the equation for Muzzle Energy (ME). Let’s use the numbers for the Steyr M40 (very similar to your Glock 23) which was one of the ‘real world’ guns used in the .40 S&W tests we did. Calculations are from Airhog.

The 165gr Federal Hydra-Shok JHP has a velocity of 943fps out of the 4″ barrel. That gives a Muzzle Energy of 325.88ft-lbs.
The 180gr Federal Hydra-Shok JHP has a velocity of 989fps out of the 4″ barrel. That gives a Muzzle Energy of 391.04ft-lbs.

OK, that would seem to indicate that the heavier bullet should cause more recoil. The ME is higher, and you’re shooting them out of the same gun.

But I’m a little wary of that example. Usually, a lighter bullet is faster than a heavier one if they have the similar powder charge, out of barrels of the same length. Here’s another example, looking at 9mm from a Beretta 92.

The Cor-Bon 90gr JHP +P has a velocity of 1522 out of the 4.875″ barrel. That gives a Muzzle Energy of 463.05ft-lbs.
The Cor-Bon 125gr JHP +P has a velocity of 1291 out of the 4.875″ barrel. That gives a Muzzle Energy of 462.72ft-lbs.

And those are very close to the same amount of ME, and should feel about the same in terms of recoil were that the only factor.

So what’s going on? Why do we see one instance where the ammo is just a bit faster in the heavier bullet (resulting in higher ME), but much slower in another instance?

I suspect that it’s probably due to differences in loadings between the different ammo. Even with ammo from the same manufacturer (in the examples above), there’s nothing saying that they are using either the same propellant OR similar amounts of the same propellant for loadings which use different bullet weights. That means that trying to generalize the amount of recoil between different bullet weights just on the basis of brand is difficult if not impossible.

Furthermore, if you’ve done any reloading, or spend some time looking over reloading data, you’ll know that even when you’re using the same propellant in the same cases, different bullet weights usually means different bullets (in terms of manufacturer and/or shape) resulting in different seating depths and overall length. It may seem to be a trivial matter, but this results in different pressure profiles (the amount of pressure within the firing chamber of the gun). Just one example, taken from the Hodgdon Reloading site, for maximum-pressure loads using  GDHPs:

The 90gr bullet with 7.0gr of Longshot powder has an overall length of 1.010″ and gives a velocity of 1,378fps, a pressure of 32,300 PSI, and would have a ME of 379.57ft-lbs.
The 115gr bullet with 6.0gr of Longshot powder has an overall length of
1.125″ and gives a velocity of 1,203fps, a pressure of 32,300 PSI and would have a ME of 369.64ft-lbs.

Note that while the heavier bullet uses a full 1.0gr less of propellant and has a longer overall length, it generates the same amount of pressure. If we drop back to the same amount of the same powder for each loading (6.0gr), then the pressure generated in the lighter bullet loading drops to 29,400 PSI, velocity drops to 1,278fps, and ME drops to 326.48ft-lbs.

But not all pressure is created equal, even if it is nominally ‘the same’. The pressure impulse also matters. That’s the curve of how the pressure rises and falls over time, which is largely related to how ‘fast’ or ‘slow’ the propellant burns. Propellants used for handgun loads tend to be very ‘fast’ (burn rapidly), so the impulse tends to be sharper.  Here’s a good explanation of the matter.

And if you think about it, the heavier the bullet used, the longer/slower it takes to start moving when the cartridge is fired. That should mean that the impulse is spread out over a slightly longer time than it would be with a lighter bullet. So in some sense, the lighter bullet would result with a ‘snappier’ feel. And that may well be what it is that you’re feeling when you experience more perceived recoil (and have controlled for all the other factors) from lighter bullets.

Other thoughts on the subject?


Jim Downey





June 15, 2014 Posted by | .38 Special, .40 S&W, 9mm Luger (9x19), Data, Discussion., Links | , , , , , , , , , , , , , , , | Leave a comment

With charts! Graphs! Slo-mo!

John Ervin at Brass Fetcher Ballistic Testing has put together another great video presentation, showing in several ways how Jacketed Hollow Point (JHP) ammo performs in comparison to Full Metal Jacket (FMJ) ammo for 9 different handgun cartridges. It’s long (22 minutes), but very nicely documents just exactly how the two different bullet styles behave at handgun velocities. Here’s the video:



The cartridges covered are .22 LR, .25 ACP, .32 ACP, .380 ACP, 9mm Makarov (9×18), 9mm Police (Ultra), .38 Special, 9mm Luger (9×19), and .45 ACP.  His data and presentation makes a great companion to our own data, and I really recommend that you set aside the time to watch the video at your earliest convenience.


Jim Downey

October 22, 2013 Posted by | .22, .25 ACP, .32 ACP, .38 Special, .380 ACP, .45 ACP, 9mm Luger (9x19), 9mm Mak, 9mm Ultra, Data, Discussion., Links | , , , , , , , , , , , , , , , , , , , , , | Leave a comment

Now, about those thunderbolts…

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:

  1. 185gr XTP bullet, .45 ACP case, .460 Rowland power  1480fps
  2. 200gr RNFP bullet, .45 ACP case, .460 Rowland power  1440fps
  3. 230gr RNFP bullet, .45 ACP case, .460 Rowland power  1350fps
  4. 250gr LFN bullet, .45 ACP case, .460 Rowland power  1250fps
  5. 230gr RNFP bullet, .45 ACP case, .45 ACP power  920fps
  6. 230gr RNFP bullet, .460 Rowland case,  .45 ACP power  925fps
  7. 185gr XTP bullet, .460 Rowland case, .460 Rowland power  1490fps
  8. 200gr RNFP bullet, .460 Rowland case, .460 Rowland power  1420fps
  9. 230gr RNFP bullet, .460 Rowland case, .460 Rowland power  1355fps
  10. 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

.460 Rowland loads

.460 Rowland loads

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:

Glock 21 magazines

Glock 21 magazines

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.


Jim Downey

October 15, 2013 Posted by | .357 Magnum, .38 Special, .45 ACP, .460 Rowland, Anecdotes, Data, Discussion., General Procedures | 20 Comments

.22 Magnum article.

My .22 Magnum article looking at our data and my conclusions is now up over on Here’s an excerpt:

Bottom line

For me, the take-away lesson from these tests is that the .22 Magnum is a cartridge that is best served out of rifle barrel. At the high end we were seeing velocities that were about 50 percent greater than what you’d get out of a similar weight bullet from a .22 LR. In terms of muzzle energy, there’s an even bigger difference: 100 percent or more power in the .22 Magnum over the .22 LR.

But when you compare the two on the low end, out of very short barrels, there’s very little if any difference: about 10 percent more velocity, perhaps 15 percent more power. What you do notice on the low end is a lot more muzzle flash from the .22 Magnum over .22 LR.

While you do see a real drop-off in velocity for the other magnums from very short barrels, they tend to start at a much higher level. Compare the .357 Magnum to the .38 Special, for example, where the velocity difference is 30 to 40 percent out of a 2-inch barrel for similar weight bullets, with a muzzle energy difference approaching 100 percent. Sure, you get a lot of noise and flash out of a .357 snubbie, but you also gain a lot of power over a .38.

Go check out the whole thing!

Jim Downey

June 5, 2013 Posted by | .22, .22WMR, .357 Magnum, .38 Special, Data, Discussion., Links | , , , , , , , , , , | 1 Comment

Up next …

… in my holster give-away is a very sweet all leather IWB of unknown make. It’s non-molded, and should accommodate almost any semi from medium to full size. Here are some pix of it with my Steyr M357:




But I also checked to see whether the following would fit:

Smaller semi-automatics and derringers do fit, but sit so far down inside the holster that they are difficult to retrieve.

Same rules as previously:

So, here’s the deal: make any kind of contribution to the Kickstarter (as little as $1.00 – I won’t mind), and enter into a drawing for a holster. Please note that this is *IN ADDITION* to the other rewards there on the Kickstarter – all perfectly good and valuable rewards. Then just come here and leave a comment, or post it on the BBTI Facebook page, or send me a Tweet. I’ll enter your name into a completely separate drawing. And each week or so while the Kickstarter is going I’ll select a name and send that person whichever holster is up for grabs. Each winner’s name will go back into the hat for the next drawing, so you have multiple chances to win (meaning that the sooner you enter, the better for you).

If you’ve already contributed to the Kickstarter, just let me know and your name will go in the hat for the first drawing (and subsequent ones).

I will draw a winner next Friday, Oct 12.

And here’s a heads-up: the final drawing will occur on Wednesday, Oct. 17, — the day after the Kickstarter ends. And that item will be a High Noon Skin Tite holster. Remember – you just need to “enter” once, and you will automatically be added to both drawings. So, what are you waiting for? Go register!


Jim Downey



October 6, 2012 Posted by | .357 SIG, .38 Special, .45 ACP, 9mm Luger (9x19), Discussion., Links | 2 Comments

Naming names.

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.

Jim Downey

December 14, 2011 Posted by | .357 Magnum, .38 Special | , , , | Leave a comment

Got brass in pocket?*

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.

Jim Downey

*with apologies to Chrissie Hynde.

December 12, 2011 Posted by | .357 Magnum, .38 Special | , , , , | 1 Comment

Excellent initial analysis & discussion.

Check out the post on The Firearm Blog titled: Fascinating Phenomenon in Cylinder Gap Data.

As I noted on our Facebook page, this is exactly the sort of discussion & analysis we hoped to engender by collecting all the data. As I have noted in the past, none of us on the BBTI team are statistics geeks, and all of us have busy lives to demand our attention elsewhere. I am perfectly happy to just do the grunt work, then turn the data loose in the world for others to play with.

Jim Downey

December 10, 2011 Posted by | .357 Magnum, .38 Special, Data, Discussion., Links | Leave a comment

It’s Up!

The new Ballistics By The Inch site is now up and running! Bigger, Faster, And with More DATA! Take a look, spread the word, let us know if there are any glitches or problems.

Jim Downey

December 1, 2011 Posted by | .22, .223, .25 ACP, .32 ACP, .32 H&R, .327 Federal Magnum, .357 Magnum, .357 SIG, .38 Special, .380 ACP, .40 S&W, .41 Magnum, .44 Magnum, .44 Special, .45 ACP, .45 Colt, .460 Rowland, 10mm, 9mm Luger (9x19), 9mm Mak, 9mm Ultra, Anecdotes, Data, Discussion., General Procedures, Links | , , , , | Leave a comment

Promises, promises.

It’s been . . . a long month. Well, no, not this one. The last one. And the one before that, to be honest.

So, while I know that a lot of folks have been eagerly awaiting the new data, let me say . . . just a little longer. Really. My Good Lady Wife, who takes care of the website, has had her hands full with a couple of other projects (including a big one of mine).

The good news is that she tells me that the new website tools she’s learned to use will help make BBTI better than ever. We’ve talked about the website redesign, and I think everyone will be pleased with the new look, the new functionality, and the new data (including .22 and .223 as well as the massive .38/.357 Gap Tests). So hang on – we’ll get it all up as soon as possible.

A quick report on site numbers, while we’re at it: August we had 290,998 hits, bringing us to a grand total of 7,155,801 hits.

For the quickest notification when the redesigned site goes ‘live’ with all the new data, subscribe to this blog, follow us on Facebook or Twitter.

Jim Downey

September 1, 2011 Posted by | .22, .357 Magnum, .38 Special, Data, Discussion., Links | 1 Comment

Lookit the purty colors!

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.

Jim Downey

July 10, 2011 Posted by | .32 ACP, .357 Magnum, .38 Special, .380 ACP, .45 ACP, Data, Discussion. | Leave a comment

Happy Father’s Day.

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.

Jim Downey

(Cross posted to the my personal blog.)

June 19, 2011 Posted by | .22, .38 Special, Anecdotes | 1 Comment