Ballistics by the inch

Reprise: Give in to the Power of the Dark Side — Converting Non-shooters

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 8/5/2011. Some additional observations at the end.

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I swear, sometimes I feel like a Sith Lord.

Friends and acquaintances will find out that I’m “into” guns. We’ll be chatting and there will be this odd moment where I can see it in their eyes: attraction, mixed with not a little fear.

If they know me at all, either through interaction or by reputation, they probably have a certain expectation. I’m a professional book & document conservator. I used to own a big art gallery. For years I wrote a column about the arts for the local newspaper. I even gained some small measure of fame as a conceptual artist.  I was the primary care-provider for my elderly mother-in-law, and have been praised for my gentleness and compassion. I’ve published two books, and am working to complete a third. Based on that, they have probably put me into a nice little box in their mental map of the world.

That I am a gun owner, someone with a CCW, and even one of the principals behind the world’s premier handgun ballistics resource usually comes as a bit of a surprise.

Hahahahahahahaha!

Yes, I like this reaction. I like what it does to people: forces them to reconsider some of their stereotypes.

And I also like that it gives me the opportunity to tempt them. To corrupt them. By taking them shooting.

What can I say? I’m evil. You know, like a Dark Lord of the Sith.

Bwahahahaha!

I don’t know how many people I have done this to. Not enough. I want to turn more of them. To have them hold a gun in their hands, to learn how they can control it, to use it safely.

Because I have found that this is key – turning their fear of something they do not understand into a tool that they can use. I tap into the strong emotion of fear, subvert it, direct it. It becomes a motivator. It helps them understand that a gun needs to be respected and handled safely.

We go through the formula of the Four Rules. They handle the revolver, the pistol, and the rifle before the ammunition ever comes out of storage. We study cartridge, and bullet, and caliber. And then I reveal the mysteries of sighting, breathing, and trigger control.

We go to the range. There is the ritual of eye and hearing protection. A review of safety commands. An invocation of the formula of the Four Rules.

I take out a .22 rifle. Load it with one round only. Tension builds. I am down range at a simple target and fire the gun.

Now they’re almost hooked. There’s anticipation, almost a hunger as they watch me.

I check the gun to make sure it is unloaded. Hand it over, have them check it. Give them one round, have them load it. Carefully, they seat the rifle, take aim. When they are ready, I have them click off the safety, put their finger on the trigger and squeeze.

You can see it in their eyes. A part of them has come alive. A part they feared. Because they did not understand it.

Usually, they get a big smile on their face. Or maybe that comes later, when we shoot one of the handguns. Sometimes it takes until we get to one of the magnums, something with a real kick to it. A big badda-BOOM! But when that happens, every one of them is hooked.

Oh, not necessarily hooked in the sense of going out and getting their own guns, and taking up shooting sports as a lifetime activity. No, hooked in the sense of understanding at an almost cellular level what the appeal is: the ability to control a kind of power they never had before.

I have opened up a whole new world for them. Shown them possibilities they didn’t know existed. Gave them a taste of the potential they had locked away.

Some of them do get hooked in the sense of wanting to learn how to use that potential. They start asking me about the nuts and bolts of getting their own gun, what it takes to pass the state CCW requirements, the advantages of this caliber or that design. They become a convert.

But even if they don’t, they no longer have an irrational fear of guns because they now know something about them – something practical and hands-on—you can almost watch their stereotyping melt and wash away. They understand that guns are not inherently “evil” – they’re just a tool, which can be used by anyone willing to put in the time to learn how to do so.

And as we pack up from our trip to the range, I’ll usually joke that I have “turned them to the Dark Side.”

Like the good Sith Lord that I am.

Wahahahaha!

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Yeah, OK, now you know why I’m not the “Jim Downey” who was an SNL writer.

But I was trying to have a little fun with the idea of ‘turning’ someone on the subject of firearms, because it is a very real experience I’ve had countless times.

 

Jim Downey

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July 30, 2017 Posted by | .22, .44 Magnum, Discussion. | , , , , , , , , , , , , , , , , , , , , , | Leave a comment

Reprise: Share and share alike — swapping weapons at the range.

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 6/09/2011. Some additional observations at the end.

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Colt Anaconda

“Wow! What the hell was that?”

I smiled, looked over at the young guys two lanes over at the public range. They had been shooting one guy’s Glock 19. I’d kept an eye on them, as I do whenever anyone else is there the same time I am. They’d been safe in how they had handled the gun, how they conducted themselves. “.44 Magnum. Wanna try it?”

“Really?” asked the one guy while the other cleared the Glock, set it down on the bench with the slide open . We were the only people on the pistol side of the range. They came walking over.

I popped the spent casings from the cylinder, dropped them in a plastic bag. Leaving the cylinder open, I handed my Anaconda to the first guy. “Sure. Ever shot a revolver?”

* * * * * * *

I don’t often go shooting at the public range. Oh, it’s close to my house and therefore convenient, but I also belong to a private club about the same distance away. However, now and then I’ll want to get out to do some shooting, but the private club will be reserved for training/classes, so I’ll slip out to the State range for a bit of recoil therapy. It’s a nice set-up, with concrete paving and nice large concrete shooting benches/tables under protection from the weather.

When I do go there, in addition to what I want to get some practice with, I’ll usually take along something a little bit unusual. Maybe a flintlock. Or the Anaconda. A derringer. My Sub2000. Something most people don’t see regularly.

It gives me an excuse to talk to people, if they express an interest in whatever it is I have with me.

* * * * * * *

“Ever shot a revolver?”

“Um, no,” said the first guy. He looked at his buddy. His buddy looked at me, shook his head.

“Well,” I said, “they’re old-school, but a lot of people still like ‘em. They’re simpler to shoot in some ways, and you can get more power in a revolver than most semis. ”

“Is this the gun that Dirty Harry used?” asked the second guy, holding the gun that his buddy had passed to him.

“Close. This is a Colt Anaconda. Dirty Harry had a Smith & Wesson Model 29. But they’re the same caliber – both .44 Magnums – and about the same size.” I took the gun back, gave them a quick lesson in how it worked, how to shoot it safely. I started ‘em with light practice loads, then a cylinder of full magnums.

A few minutes later they were both grinning like kids on Christmas.

* * * * * * *

It’s not so much that I want to meet people. There are plenty of ways to do that, and I have a lot of friends and acquaintances.

Rather, it’s a way of sharing something I know about and enjoy. Maybe do a little teaching. Maybe do a little learning. I do know a bit about guns, but there’s always more to learn.

And usually I find that if I offer to let people try my guns out, they’ll return the favor. I don’t care how good a collection you have – no one has everything.

* * * * * * *

The boom of the last full-house .44 Magnum echoed around us as the fellow opened the cylinder and handed my gun back to me. Like I said, he and his buddy were grinning like crazy.

“Man, that was great! Thanks!”

“Sure.”

“Wanna try my Glock?”

“Yeah, if you don’t mind.” I’ve shot plenty of Glocks before, and own a couple in .45 ACP, so this was nothing new to me. But it was a way of showing my respect for these guys.

We walked over to their lane. He handed me the third-generation Glock 19. It’d been well used, but seemed to be in pretty good shape. “It’s my concealed carry gun.”

“Nice. Good gun for that.”

“Thanks,” he said. I swear, he stood a little taller.

* * * * * * *

Maybe it’s a Midwestern thing. I haven’t been to shooting ranges at a lot of places elsewhere in the country. But here, whenever you go out shooting with people, everyone has to try everything. And if people seem sane at the range, many times I’ve seen folks share guns with strangers. Yeah, you wanna be a bit careful about who you hand your guns over to, but if they’ve been dangerous or inept, I’ll usually find a reason to not stick around the range very long anyway.

I’m curious – how is it in your neck of the woods? Do people share? Do you offer to let others try your guns, or ask to try theirs?

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When I originally wrote this, I hadn’t yet been to New Zealand. But as noted in this series I did for Guns.com, I discovered that sharing guns with strangers is common there as well. And since then I have also been out to other parts of the US, and seen much the same. It’s not always the case, and as noted above you have to exercise some judgment, but it seems to be a fairly widespread practice. I consider this to be a good thing.

Jim Downey

July 2, 2017 Posted by | .44 Magnum, .45 ACP, 9mm Luger (9x19), Revolver | , , , , , , , , , , , , , , | Leave a comment

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

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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.

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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

2016 in the rear-view mirror.

Happy New Year!

A quick recap of the last year: surprisingly active.

It’s interesting to see how things have evolved with BBTI over time. The last test sequence we did was the .45 Super /.450 SMC tests, with the data published in October 2015. So without new test results last year, we didn’t have the usual big spike in site visits. But we still saw a total of 447,203 visitors last year, which ain’t too shabby.

And last year we saw an evolution in who were our biggest referrers, as well. Excluding search engines, here they are in order:

  1. DefensiveCarry.com
  2. Guns.com
  3. MechTech Systems
  4. Wikipedia
  5. The Firearm Blog
  6. reddit
  7. Active Response Training
  8. Survivalist Boards
  9. The Firing Line
  10. AR15.com

All but four (Guns.com, MechTech Systems, Wikipedia, and The Firearm Blog) are discussion forums, and of those four The Firearm Blog also has a very active discussion community. MechTech Systems sells conversion kits for pistols, allowing you to turn your pistol into a carbine, so it makes perfect sense that they would link to us showing the advantage you can gain with a longer barrel.

In other words, most of the referrers are places where BBTI is being cited as a reference to help people make decisions about their firearm choices. That just makes sense, and corresponds to the email we get, thanking us for our site or asking for clarification/recommending new ammo to test. After 8 years, and with no new tests, there’s not much reason for the ‘news’ sites to mention us — but there’s still plenty of interest in the firearms community in the data we provide.

So thanks to all who share our site with others! You’re the real reason our site is a success!

 

Jim Downey

 

January 1, 2017 Posted by | .45 Super, .450 SMC, Data, Discussion., Links | , , , , , , , , , , , , , , , , , , , , , | Leave a comment

Velocity is great, but mass penetrates.

OK, kiddies, it’s time for SCIENCE!

Ballistic science, specifically. I promise to keep the math to a minimum, because I don’t like it much, either. Jim Kasper is the one who thinks in terms of equations, not me.

If you look at any of the various pages for test results on BBTI you will see that each caliber/cartridge also has a link for a Muzzle Energy (the kinetic energy of a bullet as it leaves the muzzle of a gun) graph for that set of results. That’s because Muzzle Energy can also give an idea of the effectiveness of a given ammo, since it is a calculation of both the weight of a bullet as well as the velocity it is traveling. This calculation, specifically:

E_\text{k} =\tfrac{1}{2} mv^2

Here’s what that says in English, taken from the explanation that goes with that image on Wikipedia:

The kinetic energy is equal to 1/2 the product of the mass and the square of the speed.

In other words, you multiply the weight of the bullet times the square of the velocity, then take half of whatever number you get. And that gives you the Muzzle Energy, usually (as on our site) expressed in foot-pounds of energy.

So there are two ways you can change the result: change the amount of weight, or change the amount of velocity.

But since it is the square of the velocity (the velocity times itself), changes to the velocity have a larger impact on the final amount of Muzzle Energy. That’s the reason why how the velocity changes due to barrel length is such a big deal, and why we’ve done all the research that we’ve done over the last seven years.

But while Muzzle Energy gives you a good way to compare the power and potential effectiveness of a given cartridge as a self-defense round, there are a couple of other factors to consider. A couple of VERY important factors.

One is the shape and composition of the bullet itself. There’s a very good (surprisingly good, in fact — I heartily recommend you read the whole thing) discussion of the basic shapes and how they interact with the human body in this online teaching tool intended for medical students. The relevant excerpt:

Designing a bullet for efficient transfer of energy to a particular target is not straightforward, for targets differ. To penetrate the thick hide and tough bone of an elephant, the bullet must be pointed, of small diameter, and durable enough to resist disintegration. However, such a bullet would penetrate most human tissues like a spear, doing little more damage than a knife wound. A bullet designed to damage human tissues would need some sort of “brakes” so that all the KE was transmitted to the target.

It is easier to design features that aid deceleration of a larger, slower moving bullet in tissues than a small, high velocity bullet. Such measures include shape modifications like round (round nose), flattened (wadcutter), or cupped (hollowpoint) bullet nose. Round nose bullets provide the least braking, are usually jacketed, and are useful mostly in low velocity handguns. The wadcutter design provides the most braking from shape alone, is not jacketed, and is used in low velocity handguns (often for target practice). A semi-wadcutter design is intermediate between the round nose and wadcutter and is useful at medium velocity. Hollowpoint bullet design facilitates turning the bullet “inside out” and flattening the front, referred to as “expansion.” Expansion reliably occurs only at velocities exceeding 1200 fps, so is suited only to the highest velocity handguns.

Now, while that last bit about needing to exceed 1200 fps may have been true, or a ‘good enough’ approximation a few years ago, it isn’t entirely true today. There has been a significant improvement in bullet design in the last two decades (and these innovations continue at a rapid pace), so that there are now plenty of handgun loads available which will reliably expand as intended in the velocity range expected from the round.

The other REALLY important consideration in bullet effectiveness is penetration. This is so important, in fact, that it is the major criteria used by the FBI and others in assessing performance. From Wikipedia:

According to Dr. Martin Fackler and the International Wound Ballistics Association (IWBA), between 12.5 and 14 inches (318 and 356 mm) of penetration in calibrated tissue simulant is optimal performance for a bullet which is meant to be used defensively, against a human adversary. They also believe that penetration is one of the most important factors when choosing a bullet (and that the number one factor is shot placement). If the bullet penetrates less than their guidelines, it is inadequate, and if it penetrates more, it is still satisfactory though not optimal. The FBI’s penetration requirement is very similar at 12 to 18 inches (305 to 457 mm).

A penetration depth of 12.5 to 14 inches (318 and 356 mm) may seem excessive, but a bullet sheds velocity—and crushes a narrower hole—as it penetrates deeper, while losing velocity, so the bullet might be crushing a very small amount of tissue (simulating an “ice pick” injury) during its last two or three inches of travel, giving only between 9.5 and 12 inches of effective wide-area penetration.

As noted above, the design of the bullet can have a substantial effect on how well it penetrates. But another big factor is the weight, or mass, of the bullet relative to its cross-section — this is called ‘sectional density‘. Simply put, a bullet with a large cross-section and high mass will penetrate more than a bullet with the same cross-section but low mass moving at the same speed. It isn’t penetration, but think of how hard a baseball hits versus a whiffleball moving at the same speed. They’re basically the same size, but the mass is what makes a big difference. (See also ‘ballistic coefficient‘).

With me so far?

OK, let’s go all the way back up to the top where I discussed Muzzle Energy. See the equation? Right. Let’s use the baseball/whiffleball analogy again. Let’s say that the baseball weighs 5.0 ounces, which is 2,187.5 grains. And the whiffleball weighs 2/3 of an ounce, or 291.8 grains. A pitcher can throw either ball at say 60 mph, which is 88 fps. That means (using this calculator) that the Kinetic Energy of a baseball when it leaves the pitcher’s hand is  37 foot-pounds, and the whiffleball is just 5 foot-pounds. Got that?

But let’s say that because it is so light, the pitcher can throw the wiffleball twice as fast as he can throw a baseball. That now boosts the Kinetic Energy of the whiffleball to 20 foot-pounds.

And if you triple the velocity of the whiffleball? That gives it a Kinetic Energy of 45 foot-pounds. Yeah, more than the baseball traveling at 88 fps.

OK then.

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

What is the top line on that graph? Yeah, Liberty Civil Defense +P 78 gr JHP.  It has almost 861 foot-pounds of energy, which is more than any other round included in those tests. By the Muzzle Energy measure, this is clearly the superior round.

But would it penetrate enough?

Maybe. Brass Fetcher doesn’t list the Liberty Civil Defense +P 78 gr JHP. But they did test a 90 gr RBCD round, which penetrated to 12.0″ and only expanded by 0.269 square inch. Compare that to the other bullets listed on his page, and you’ll see that while the depth of penetration isn’t too bad when compared to other, heavier, bullets, that round is tied with one other for the least amount of expansion.

Driving a lightweight bullet much, much faster makes the Muzzle Energy look very impressive. Just the velocity of the Liberty Civil Defense +P 78 gr JHP is impressive — 1865 fps out of a 5″ barrel is at least 50% faster than any other round on our test results page, and almost 400 fps faster than even the hottest of the .45 Super loads tested.

But how well would it actually penetrate? Without formally testing it, we can’t say for sure. But I am skeptical. I’m not going to volunteer to getting shot with one of the things (or even hit with a whiffleball traveling 180 mph), but I’m also not going to rely on it to work as it has to in the real world, where deep penetration is critical. I want a bullet with enough punch to get through a light barrier, if necessary. Like this video from Hickok45, via The Firearm Blog:

Personally, I prefer a heavier bullet. Ideally, I want one which is also going to have a fair amount of velocity behind it (which is why I have adapted my .45s to handle the .45 Super). All things being equal (sectional density, bullet configuration and composition), velocity is great, but mass is what penetrates.

Jim Downey

November 8, 2015 Posted by | .45 ACP, Data, Discussion. | , , , , , , , , , , , , , , , , , , , , , , , , , , , | 3 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

No matter which way you look …

…whether back over 2014, or forward into 2015, things are pretty good vis-a-vis BBTI.

Yeah, 2014 was pretty good. We didn’t do any formal testing, though I did some informal testing and a fair number of reviews of new guns or guns which were just new to me.  Having the chance to do those now and again is enjoyable, without having the same deadline pressures I had when I was doing regular columns and reviews for Guns.com.

The numbers also look pretty good for 2014. This blog went from about 12,000 visits in 2013 to 22,000 last year – nearly double. And the BBTI site itself jumped from 243,230 visitors in 2013 to 318,304 visitors in 2014 — an increase of about a third. Visits have also continued to climb pretty steadily from day-to-day, with typically about 1,250 or so daily by the end of the year. Given that we didn’t do any new testing, that’s pretty impressive.

And of course, we’d like to thank all who linked to us over the past year. Here’s the top ten referring sites for 2014, excluding search engines and Wikipedia:

  1. thefiringline.com
  2. defensivecarry.com
  3. guns.com
  4. thefirearmblog.com
  5. ar15.com
  6. gunsamerica.com
  7. reddit.com
  8. thetruthaboutguns.com
  9. rimfirecentral.com
  10. survivalistboards.com

How about the year to come, then?

Well, we’re planning on doing one largish series of tests, to cover .45 Super, .450 SMC, and a number of additional .45 ACP loadings. We haven’t yet set a date for this sequence, but I will post a note about it here and on our Facebook page once plans solidify.

And behind the scenes, improvements continue at the BBTI website. We recently upgraded our hosting set-up, to shift over to more modern software technology. We’ve started discussing how we can do better presentations of our graphs and spreadsheets. I would still very much like to work with someone to develop a mobile app — if you have the necessary skill set to do that, please drop me a note. And whenever someone finds a glitch in our data or how the site renders for them, we try and make the corrections. None of this is very obvious, but it is all a lot of work, and I’d like to once again thank our web guru (and my lovely wife) at Coeurbois Graphic Design for her efforts.

Lastly, thanks to all who use the site regularly, who cite us in online discussions, who help to spread the word. And especially, I would like to thank all who have donated to BBTI in the last year — your tangible contributions make a difference, and help to offset our ongoing costs.

Happy New Year!

 

Jim Downey

January 2, 2015 Posted by | .45 ACP, .45 Super, .450 SMC, Boberg Arms, Data, Discussion., Links | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , | 1 Comment