Ballistics by the inch

Reprise: It’s Not the Length of Your Barrel, It’s How You Use It

My friends over at the Liberal Gun Club asked if they could have my BBTI blog entries cross-posted on their site. 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 3/7/2011. Some additional observations at the end.

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“What is the best barrel length?”

It’s a question I get a lot, thanks to my involvement in Ballistics By The Inch. And invariably, I say in response: “it depends.” As in, it depends on what you’re going to use it for.

OK, first thing: I’m talking about pistol cartridges, not rifle cartridges. Got that? Pistol cartridges.

That’s what we studied with our BBTI project (actually, continue to study, since we’ve done several expansions of the cartridges and ammunition tested already, and have another big expansion coming up the beginning of May.) Now that we’ve cleared that up . . .

Different barrel lengths are good for different purposes. The longer the barrel, the longer the sight radius, and so the easier it is to be accurate with the gun. The shorter the barrel, the easier it is to conceal.

And barrel length has an effect on the velocity of a bullet (and hence the power of that bullet.) How much of an effect? Well, it depends.

No, seriously, it depends. Do not believe it when someone tells you “oh, the rule of thumb is about 75 (or 25 or 100 or any other number) feet per second for each inch of barrel.” That number may be right for one given ammunition in one given gun for one given inch of barrel length – but it will not hold true as a general case. Don’t just take my word on this – look at the actual numbers from tests we conducted, using almost 10,000 rounds of ammunition. You can go to the BBTI site and see the data for yourself (it’s all free, with no advertising or anything), but here are two examples:

Cor Bon 165gr JHP +P .45 ACP ammo was tested at 1001 fps with a 2″ barrel. That jumps to 1050 fps with a 3″ barrel, or an increase of about 50 fps. Going to a 4″ barrel you get 1163 fps, or an increase of 113 fps. But when you go from an 10″ barrel to a 11″ barrel, you only get an increase of 23 fps.

Let’s look at Federal Hydra-Shok 230gr JHP .45 ACP. It starts at 754 fps with a 2″ barrel, and jumps to 787 fps out of a 3″ barrel – an increase of 33 fps.  Go to the 4″ barrel and it tested at 865 fps – an increase of 78 fps. And when you go from an 10″ barrel to a 11″ barrel, you only get an increase of 4 fps.

Do you see my point? It not only varies by ammunition, it also varies by which inch of the barrel you are talking about – the inch between 3 and 4 sees a lot more increase than the inch between 10 and 11.

Almost all handgun cartridges show this effect, and it makes sense: pistol cartridges use a fast burning powder, but it still needs a little bit of time to completely combust. The highest acceleration comes at first, and then usually handgun bullets plateau out somewhere between 6″ and 10″, with little additional velocity with longer barrels past that point. The graph of our first example shows this very well:

Some cartridges even show velocity starting to drop off with longer barrels, as the friction of the bullet passing through the barrel overcomes any additional boost from the gunpowder. Notably, the “magnum” cartridges (.327, .357, .41, and .44) all show a continued climb in velocity/power all the way out to 18″ of barrel length (the maximum we test), though the amount of increase tends to get smaller and smaller the longer the barrel.

So, back to “it depends”: if you want a lever-gun or carbine, which uses a pistol cartridge, you’re best off using one of the magnums if you want maximum power. If, however, you want to use a carbine for an additional power boost and better aiming, one with a barrel length somewhere in the “plateau” for a given cartridge makes sense (and this is why subguns typically have barrels in the 8 – 10″ range).

For a hunting pistol, you probably want to have a barrel of 6″ to 8″ to get a lot of the additional power and still have it manageable. This barrel length will also give you a nice big sight radius for accuracy, making it good for hunting or target shooting.

How about for concealed carry? The shorter the barrel, the better, right? Well, if you look through all our data, you’ll see that usually, most cartridges see the greatest jump in velocity (and hence power) from 2″ to 4″. Now, the smaller the caliber and the lighter the bullet, the more the big jump tends to come right up front – from 2″ to 3″. The larger the caliber and the heavier the bullet, the more it tends to come a little later, from 3″ to 4″. Still, you can decide for yourself whether the trade-off in less power for ease of carry is worth it.

And good news for the revolver fans: because the cylinder basically functions to extend the barrel, your 2″ snubby actually functions more like a gun with a 3.5″ – 4″ barrel. Though there is some velocity/power loss due to the cylinder gap. How much loss? That is actually the next thing we’ll be testing, but I’d bet that . . . it depends.

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Since I wrote that six years ago, we’ve done a LOT more testing at BBTI, and have now shot more than 25,000 rounds and greatly expanded our data. The cylinder gap tests mentioned above did indeed show that the amount of loss did vary according to a number of factors, but for the most part established that the effect wasn’t as large as many people thought. And we found an interesting exception to the “magnum” rule in one of our most recent tests: it turns out that the .45 Super cartridge behaves like a true magnum, by continuing to gain more power the longer the barrel, until at carbine lengths it is on a par with (or even exceeds) the .460 Rowland cartridge. Since the .45 Super is based on the .45 ACP cartridge, we expected it to perform like that cartridge and level off at about 10″, but it clearly continues to gain out to at least 18″.

I also want to add a couple of quick comments about how concealed-carry guns have changed, though this is more just personal observation than any kind of rigorous research. I think that as concealed-carry has continued to expand, more gear is on the market to make it easier to do, and I think for that reason some people are able to carry slightly larger guns and there are more guns available with barrel length in the 4″ – 5″ range. In addition, sight/optics/laser options have continued to improve, making simple sight radius less of a factor — meaning that for those who do want to carry a smaller gun, it is easier to use it well (though having better sights/optics/lasers is NOT a substitute for practice!) I expect that both these trends will continue.

Jim Downey

March 26, 2017 Posted by | .327 Federal Magnum, .357 Magnum, .41 Magnum, .44 Magnum, .45 ACP, .45 Super, .450 SMC, .460 Rowland, Data, Discussion., Revolver | , , , , , , , , , , , , , , , , , , , , , , , | Leave a comment

Reprise: So, You Say You Want Some Self-Defense Ammo?

My friends over at the Liberal Gun Club asked if they could have my BBTI blog entries cross-posted on their site. This is the second 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 2/16/2011. Some additional observations at the end.

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You need to choose self-defense ammunition for your gun. Simple, right? Just get the biggest, the baddest, the most powerful ammunition in the correct caliber for your gun, and you’re set, right?

Wrong. Wrong, on so many levels.  For a whole bunch of reasons. We’ll get to that.

Shooters have earned the reputation as an opinionated breed and arguments over ammunition are a staple of firearms discussions, and have been for at least the last couple of decades. Much of this stems from the fact that every week it seems, you’ll see “fresh” claims from manufacturers touting this new bullet design or that new improvement to the gunpowder purportedly to maximize power or minimize flash.  And the truth is there have been a lot of improvements to ammunition in recent years, but, if you don’t cut through the hype you can easily find yourself over-emphasizing the importance of featured improvement in any given ammunition.

Perhaps it’s best to consider it by way of example.  While the basic hollowpoint design has been around since the 19th century, I remember when simple wadcutters or ball ammunition was about all that was available for most handguns. Cagey folks would sometimes score the front of a wadcutter with a knife (sometimes in a precarious manner—please don’t do this Taxi Driver-style with live ammunition) to help it ‘open up’ on impact. Jacketed soft point ammunition was considered “high tech” and thus distrusted. And yet, these simple bullets stopped a lot of attacks, killed a lot of people and saved a lot of lives.

I’m not saying that you don’t want good, modern, self-defense ammunition. You probably do. I sure as hell do. I want a bullet designed to open up to maximum size and still penetrate properly at the velocity expected when using it. If you are ever in a situation where you need to use a firearm for self-defense, you want it to be as effective as possible in stopping a threat, as quickly as possible.

Modern firearms are not magic wands. They are not science-fiction zap guns. How they work is they cause a small piece of metal to impact a body with a variable amount of force. That small piece of metal can cause more or less damage, depending on what it hits and how hard, and how the bullet behaves. Here’s the key that a lot of people forget: as a general rule, location trumps power.  All you have to do is meditate on the fact that a miss with a .44 magnum is nowhere  near as effective as a hit with a .25 ACP.  And when I say “a miss” I’m talking about any shot which does not hit the central nervous system, a major organ, or a main blood vessel (and even then it matters exactly which of these are hit, and how). Plenty of people have recovered from being shot multiple times with a .45. Plenty of people have been killed by a well-placed .22 round.

Hitting your target is what is most important and for most of us that is harder to do with over-powered ammunition we’re not used to shooting regularly. Chances are that under the stress of an actual encounter, your first shot may not be effective at stopping an attack. That means follow-up shots will be needed, and you’d better be able to do so accurately. If you can’t get back on target because of extreme recoil, then what’s the point of all that extra power?  If you can’t get back on target because you’ve been blinded by the flash of extra powder burning after it leaves the muzzle, well hell, that’s not good either.

Nestled up alongside power is having an ammunition that will actually work well in your gun. Some guns are notoriously ammunition sensitive and you  don’t want to just be finding out  your gun doesn’t particularly care for an ammo when you really need it to go boom. Check with others (friends or online forums) who have your type of gun, and see what ammo works for them. Then test it yourself, in your actual gun. Some people won’t carry a particular ammunition until they have run a couple of hundred rounds of that ammunition through their gun. Personally, I’ll run a box or two through the gun and consider that sufficient;  you’ll know after that if your gun generally handles  that ammunition with any problems.

So, once you have an idea of what ammunition will work in your particular gun, how do you choose between brands? As I’ve previously discussed, you can’t necessarily trust manufacturer hype. So, how to judge?

Well, you can do some research online. The fellows at The Box of Truth have done a lot of informal testing of ammunition to see how different rounds penetrate and perform. The Brass Fetcher has done a lot of more formal testing using ballistic gelatin. Ballistics By The Inch (which is yours truly’s site) has a lot of data showing velocity for different ammunition. And most gun forums will have anecdotal testing done by members, which can provide a lot of insight.

But don’t over-think this. Handguns are handguns. Yeah, some are more powerful than others, but all are compromises – hitting your target is the single most important thing. And like I said, ammunition can help, but only to a certain extent. We’re talking marginal benefits, at best, whatever the manufacturers claim. So relax;  all of the big name brands are probably adequate, and you’d be hard pressed to make a truly bad decision, so long as the ammunition will function reliably in your gun and you can hit your target with it.

Of course, as you do more research, and get more experience, you’ll probably find you like some ammunition more than others, for whatever reason. That’s fine. It just means that you’re ready to join in the (generally genial) arguments over such matters with other firearms owners. Welcome to the club.

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Some additional thoughts, six years later …

Bullet design has continued to improve, with new and occasionally odd-looking designs and materials being introduced regularly. Some of these are *really* interesting, but I keep coming back to the basic truth that the most important factor is hitting the target. No super-corkscrew-unobtanium bullet designed to penetrate all known barriers but still stop inside a bad guy is worth a damn if you miss hitting your target.

And that means practice (and training, if appropriate) is more important than hardware. What I, and a lot of shooters concerned about their self-defense skill, will do is to use practice ammo for training when they go to the range, to keep their basic skill set honed. And then supplement that with a magazine or two (or a cylinder or two) of their carry ammo, so they refresh their knowledge of how it feels and behaves in their gun. This can help keep practice costs down (since good SD ammo can be expensive), but also keeps carry ammo fresh.

Jim Downey

March 18, 2017 Posted by | .22, .25 ACP, .44 Magnum, .45 ACP, Data, Discussion. | , , , , , , , , , , , , , , , , , , , , , , | 2 Comments

Reprise: Ammo by the Numbers: What Do All Those Numbers on My Box of Ammo Mean?

My friends over at the Liberal Gun Club asked if they could have my BBTI blog entries cross-posted on their site. I said yes, and got to thinking that perhaps I would revisit 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 the first article I wrote for Guns.com, and it originally ran 2/9/2011. Some additional observations at the end.

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One of the most bewildering moments for a relatively novice shooter is selecting ammunition. Go online, or into a big-box store, or even into your local gun shop and you can be confronted with a huge array of choices in any given caliber or cartridge design. Most of the boxes have a sort of ‘code’ on the side; some have little charts or even graphs on the bottom. But which one do you want? What does this stuff even mean? Do claims of a certain velocity or energy tell you anything?

Let’s take a look at some terms, first.

Most prominently displayed figure on the box, is the cartridge: .45 Auto, .357 Magnum, 9mm Luger and so forth. There can be some confusion on this, so be sure to check your gun to see what it says on the side of the barrel or slide, or is specified in the owner’s manual  – that’s the only kind of ammunition you want. There is a difference between a .45 Colt and a .45 Auto, or a .357 Magnum and a .357 Sig, just for a couple of examples – make sure you get the kind of cartridge that your gun handles. It may seem silly to bring this up, but even experienced shooters can accidentally grab the wrong box of ammo sometimes – I have made this very mistake myself.

Next you’ll find a number, listed with either “grain” or just “gr.” This tells you the weight of the actual bullet.

Then there will be some variety of description of the bullet, indicating intended use. It could say “target” or “range” or just “ball” – all of these mean a basic bullet, probably with a slightly rounded nose, or perhaps a conical shape, or just a simple cylinder which might also have a small flat conical front (sometimes called a semiwadcutter or “SWC”). The actual bullet may be just lead or may have a “full metal jacket” – a thin layer of some harder metal such as a copper alloy. “Hunting” usually means a “JSP” – jacketed soft point. “Self-defense” usually indicates some variety of “JHP” – jacketed hollow point. Some premium self-defense ammunition uses proprietary terms such as “DPX,” “Hydra-Shok,” and “GDHP” but these are largely marketing terms you don’t need to worry about too much, at least at first.

Terms “+P” or “+P+” indicate that the cartridge is somewhat more powerful (“over-pressure”) than standard for that cartridge. Most modern guns can handle a limited diet of such cartridges, but older guns may not. If in doubt, check your gun’s owner’s manual or ask a gunsmith.

Particularly on premium defensive ammunition you may see some indication of the “velocity” or “energy” of the cartridge. Here in the US, velocity is given in “fps” – feet per second. “Energy” is given in “ft/lbs” – foot-pounds (the amount of energy needed to lift one pound one foot off the ground, not the confusingly similar term used to measure torque). The faster a bullet, and the more it weighs, the more kinetic energy it has. Sometimes a little chart will be given, showing velocity and energy at the muzzle of the gun, then at one or more distances (bullets lose velocity and energy due to air resistance).

While more velocity and more energy are generally good things for defensive ammunition, don’t get too hung up on these numbers. Why? Because the manufacturers don’t really give you enough information to compare one ammunition to another one easily. They don’t tell you what the barrel length used was (and this can have a huge impact on velocity). They don’t tell you the type of gun used (a revolver and a semi-auto both have different effects on the speed of a bullet). And they don’t tell you the type of barrel used (some barrels are known to be ‘faster’ than others.)

Then why bother at all with this information? Because it can help in some instances. If all you’re going to do is just use your gun for ‘plinking’, you can probably get whatever ammunition is cheapest and suitable for your gun.

But if you’re after accurate and consistent target shooting, or use your gun for hunting or defensive purposes, you want to be choosy. Once you find ammunition you and your gun like, you want to try to stay as close to that ammunition as you can. What do I mean by ammunition you and your gun like?

Some guns will feed and fire some ammunition better than others. The shape of the bullet can make a difference. The weight of the bullet can make a difference. The amount of energy can make a difference.

Ammunition with greater energy will cause your gun to have greater recoil (‘kick’), and that can make it more difficult to shoot. Ammunition which is touted for being “reduced recoil” likely has less energy than other ammunition, that can make it less effective for hunting or self-defense.

Using the same amount of gunpowder, a lighter bullet will go faster than a heavier one. But a heavier bullet will generally slow down less due to air resistance, and will generally penetrate deeper into whatever you are shooting at.

“Target,” “ball,” and similarly-termed ammo is usually less expensive, and is good for practice. It is less ideal for self-defense purposes, because the bullet does not expand the way a hollow point or “JHP” is designed to when it hits flesh. “Hunting” ammunition is usually designed to expand some, but to still penetrate deeply.

Where should you begin?  Start out seeing what ammunition others who own a gun like yours use. None of your buddies shooting a gun like yours?  Maybe do a little checking online – many firearms forums post anecdotal information showing testing members have done, and there are some good sites that do more rigorous testing for velocity and penetration. See what is recommended, and give it a try.

So, beyond the numbers, what’s a good general rule when pairing ammo with a gun?  I’m of the opinion that, ideally, you should try out a box or two of different types of premium ammunition first to see which brands and type your gun likes. Using this as your guide, you can then launch the search for less expensive practice ammunition that is similar in weight and velocity, because that will behave similarly to your premium ammo in terms of point-of-impact and felt recoil.

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Since I wrote this six years ago, there have been some noticeable changes in the ammunition industry, and now most manufacturers provide at least some basic information as to how the numbers they use were gathered — what barrel length, sometimes what gun they used — to make it a little easier for a consumer to know what they are buying. I have been told directly by some engineers and sales people at different companies that this is due to BBTI‘s testing and publication of our data, which has forced manufacturers to be more forthcoming.

Something else we’ve experienced in the intervening years was the Great Ammo Shortage (which for the most part has now passed). But it taught the wisdom of always keeping a bit more ammo on hand than you might otherwise need for a single trip to the range, to help ride out similar shortages in the future. I’ll address ammo storage issues in a future blog post.

Jim Downey

March 14, 2017 Posted by | .357 Magnum, .357 SIG, .45 ACP, .45 Colt, 9mm Luger (9x19), Data, Discussion. | , , , , , , , , , , , , , , , , , | 1 Comment