Is the 40 done?

[JohnKSa]

When you set the question within the narrow limits of caliber you make a significant error.

Not if that's the range that is of interest.

In this case, it is exactly the range that is of interest since we're discussing a caliber in the service pistol performance class.

What doesn't make sense is to try to widen the scope to include discussions of calibers outside of the range that is of interest.

All these caliber overlap in power in a number of their loads and have only small differences in diameter that may or may not, the diameter that is, make a difference.

Yeah, that's exactly my point. Except that I go further and say that it doesn't make a practical difference because no one has been able to show that it does. If it did make a practical difference, then it would be relatively simple to show it existed.

The real issue is with the way the question here is posed. You employ caliber, rather than power.

Ok, if you prefer, I will restate my comment.

"What differences do the power differences in the service pistol performance class make in terms of the speed in stopping fights and what do the power differences in the service pistol performance class make in terms of the number of shots required by each of the members in the class to get the job done compared to others in the class?"

We can talk about caliber, or we can talk about the power differences due to caliber. It doesn't really make any difference how it's couched. The bottom line is that no one has any evidence that the terminal balllistics due to caliber/power differences within the class of interest make any practically significant difference in the outcome of the real-world shootings.

If we ask does better bullet construction and more energy aid in terminal performance?

Clearly that's the question that is important to you. If that's true, then you're done. You can look at the differences in terminal ballistics and make the call based on that.

I've said repeatedly that I don't care about that for the simple reason that no one has been able to show that the differences in terminal ballistics within service pistol performance class make any practically significant difference in the outcome of real-world shootings.

If you want to hang your hat on differences that no one can prove actually make a difference on the street, then that's your prerogative. I choose not to go that direction. I choose to ignore an "advantage" that no one can prove even exists in preference for the many advantages that even the most oblivious people can see do exist and are practically significant.

You also ask a question that has no real world meaning because there is no real world way of proving it, or even showing it, one way or another.

IF there really were a practically significant difference in the street performance, there would be a very simple real-world way of proving it.

It is precisely the fact that no one has been able to prove that there's any difference in real-world performance that makes it obvious that the difference can't be practically significant.

For decades people have been working this problem looking for the proof that there's a difference in real-world shooting performance and yet no one has been able to find the difference. Some people want to believe so badly that that this difference that is so elusive that no one can prove it exists is really there that they miss the obvious. If it's impossible to show it exists (as you admit), how can it provide a practical benefit? How could a practical benefit be undetectable?

If there were a practical benefit in real-world shootings, then, by definition, it would be possible to demonstrate that difference by looking at the outcome of real world shootings.

It's a mystical question.

An excellent choice of words.

It's not a mystical question for me. I look for evidence and no one has any. I decide that if there's a difference that is so small no one can find it even after decades of looking, it can't be practically significant. So I dismiss it and move on.

It's only mystical to people who choose to keep believing in something that no one can prove exists.

 

[tipoc]

I stated: that the relatively small differences in bullet diameter from one caliber to another may or may not make a difference in the bullet's terminal effectiveness.

You replied:

Yeah, that's exactly my point. Except that I go further and say that it doesn't make a practical difference because no one has been able to show that it does. If it did make a practical difference, then it would be relatively simple to show it existed.

Further:

Ok, if you prefer, I will restate my comment.

"What differences do the power differences in the service pistol performance class make in terms of the speed in stopping fights and what do the power differences in the service pistol performance class make in terms of the number of shots required by each of the members in the class to get the job done compared to others in the class?"

We can talk about caliber, or we can talk about the power differences due to caliber. It doesn't really make any difference how it's couched. The bottom line is that no one has any evidence that the terminal balllistics due to caliber/power differences within the class of interest make any practically significant difference in the outcome of the real-world shootings.

You mis-state or misunderstand my position. The differences in bullet design and in the power of a bullet even within caliber are more likely to make a difference in the terminal effectiveness of a bullet than a less powerful round, even within the same caliber. That's what I've argued in this thread.

It's also what led the U.S. Army and the FBI to upgrade the 9mm ammo that they have been using. In the case of the FBI they return to the obvious benefits that the 9mm brings and have increased the effectiveness of the 9mm with improved bullets and more power.

These moves were made not because no one can tell the difference between a more powerful round from a less powerful one but precisely because they can. They increased the effectiveness of the 9mm and also got the all around benefits of that round (over the 40 S&W or 45 acp) for military and law enforcement use.

I've argued that better bullet design and increased power aid in the terminal effectiveness of a bullet over both caliber and within caliber. If you believe that no evidence exists for that, yet it would be simple to prove or disprove...how would you prove it? Or even show that there was no difference that made it matter at all.

tipoc

 

[Forte S+W]

Uh-Oh! You know the end is near when a thread has reached the point in which there are back-and-forth multi-quote debates going on.

Frankly I don't understand why people have to argue as if there's exists an all-purpose, one-size-fits all cartridge which magically transcends individual limitations and instantly turns everyone who wields it into a Jerry Miculek-esq marksman.
But then again, unless I'm very much mistaken, it seems as if many of the folks who engage in such feverish debates are motivated in large part due to their inability to accept the limitations of themselves and/or others, resulting in the exchange of petty strawman arguments like "If you carry anything less than [insert caliber/cartridge here] then you aren't taking your self-defense seriously!" or alternatively "If you carry anything more than [insert caliber/cartridge here] than you're just a big, dumb oaf or trying to compensate for something!"

Personally, I have chosen .40 S&W for self-defense because it works for me, but I accept that it doesn't work for everyone and don't hold it in any particular regard as a self-defense cartridge. Frankly, I'm comfortable with anything from .380 ACP and upwards.

 

[JohnKSa]

Frankly I don't understand why people have to argue as if there's exists an all-purpose, one-size-fits all cartridge which magically transcends individual limitations and instantly turns everyone who wields it into a Jerry Miculek-esq marksman.

Well, I think that a lot of it is that believing something like that takes a lot of pressure off the shooter and puts it onto the weapon and ammunition. But it doesn't make sense because it's obviously not realistic.

But then again, unless I'm very much mistaken, it seems as if many of the folks who engage in such feverish debates are motivated in large part due to their inability to accept the limitations of themselves and/or others, resulting in the exchange of petty strawman arguments like "If you carry anything less than [insert caliber/cartridge here] then you aren't taking your self-defense seriously!" or alternatively "If you carry anything more than [insert caliber/cartridge here] than you're just a big, dumb oaf or trying to compensate for something!"

Fortunately, I don't think anyone's made any statements along those lines on this thread. If I missed them, please report them to the staff using the report post feature.

I stated: that the relatively small differences in bullet diameter from one caliber to another may or may not make a difference in the bullet's terminal effectiveness.

I read that. If you could say they did make a difference, you would. The fact that the strongest statement you feel you can make is that they "may or may not" make a difference is telling.

I go a step further and say that they do not make a difference because there's no evidence that they do.

You mis-state or misunderstand my position. The differences in bullet design and in the power of a bullet even within caliber are more likely to make a difference in the terminal effectiveness of a bullet than a less powerful round, even within the same caliber. That's what I've argued in this thread.

I know exactly what you've argued in this thread. The problem is that you don't have any evidence that the differences in "design", power" within caliber (or even within a caliber class) make any practically significant difference in gunfights. If you did, you would have shut my argument down the first time I made it and we would have been done right away.

You can talk about how you think that they're "more likely to make a difference" under certain circumstances, but reality is that if they do make a difference, it's so small that no one can detect it and therefore so small that it can't possible be practically significant.

These moves were made not because no one can tell the difference between a more powerful round from a less powerful one but precisely because they can.

Of course they can. The problem comes when they try to show that the difference in power makes a difference in gunfights. When ANYONE tries to show that. Because no one has been able to. If I'm wrong about that, then where's the evidence?

I've said this a few times now: If you are content to hang your hat on the measurable differences in terminal ballistics then you're done with this topic. It's not hard to measure differences in kinetic energy or differences in momentum, or bullet weight differences, or diameter differences. If that's what matters to you and you find a combination of parameters that makes you feel good, then go with it.

The problem is that you aren't content to do that--you want to take the next step and claim that your preferred combination of parameters will provide you with a practically significant benefit in a real-world gunfight. That's problematic because there's absolutely no evidence to show that the terminal ballistics differences within the service pistol caliber class make any practically significant differences in how fast fights are stopped or how many rounds it takes to effect a stop.

 

[tipoc]

The problem is that you aren't content to do that--you want to take the next step and claim that your preferred combination of parameters will provide you with a practically significant benefit in a real-world gunfight. That's problematic because there's absolutely no evidence to show that the terminal ballistics differences within the service pistol caliber class make any practically significant differences in how fast fights are stopped or how many rounds it takes to effect a stop.

No one has shown, by the parameters that you ask for, that there is a "practical difference" between the 38 Spl. and the 357 magnum in an actual gunfight. By the parameters that you want no one can or has shown that there is a difference between the 45 Colt or the 38 Spl. in a real world gunfight. That is because the parameters you ask for are without practical meaning or way of being measured.

By the ways that can be measured they do have a meaning and implications.

My position is simple..."Bring enough gun". Bring a better bullet with a better load. When possible use more power, sometimes that's a better load and bullet sometimes a larger caliber, it's more likely results will go your way.

When I point out that the Army recently did just that in their choice of improved 9mm ammo your only reply is that there is no proof that the ammo will do any better than the older 9mm ammo designs in real world gunfights. You have the same reply to the FBI's upgraded 9mm ammo. I disagree with your conclusion on this matter.

So we disagree on this.

Where we agree is that the shooter should choose a gun that they shoot well with good ammo matched to the task they have the gun for. That a well placed shot makes the difference. That caliber or power is less important than shot placement, accuracy and speed.

tipoc

 

[agtman]

Is the 40 done?

Yep ...

A 'compromise 10mm' without the 10mm's power or accuracy.

The .40's only saving virtue was that you could stuff 12-15 rds into a 9mm-sized gun and hope to please the wee-handed folks.

Except it didn't.

The same whiners who complained that an large-framed 10mm pistol was too big or heavy for all-day carry, almost immediately started whining that the smaller .40 pistol was 'too snappy' for their wuddle hands.

So good riddance. I say ...

Can't handle a 10mm or .45? Fine, no problem. The 9-minimeter is still around and available in the more diminutive pistols.

 

[TunnelRat]

Yep ...



A 'compromise 10mm' without the 10mm's power or accuracy.



The .40's only saving virtue was that you could stuff 12-15 rds into a 9mm-sized gun and hope to please the wee-handed folks.



Except it didn't.



The same whiners who complained that an large-framed 10mm pistol was too big or heavy for all-day carry, almost immediately started whining that the smaller .40 pistol was 'too snappy' for their wuddle hands.



So good riddance. I say ...



Can't handle a 10mm or .45? Fine, no problem. The 9-minimeter is still around and available in the more diminutive pistols.

Sent from my Pixel 2 using Tapatalk

 

[Forte S+W]

It never ceases to amuse me when folks immediately display their ignorance by stating that .40 S&W is just a watered down 10mm Auto when in reality the FBI's .40 S&W load is actually pretty close to the performance of Colonel Jeff Cooper's original specifications for the 10mm Auto cartridge. Norma decided that Cooper's load wasn't powerful enough from a marketing standpoint and thus made the unauthorized executive decision to amp up the load, which is the "full-power" load everyone erroneously attributes to Jeff Cooper.

So yeah, all of you folks who walk around calling .40 S&W; "fordy short n' wimpy" only to turn around and praise Jeff Cooper for his amazing 10mm Auto cartridge have no idea what you're talking about.

Jeff Cooper designed the 10mm Auto to be the ultimate law enforcement cartridge, and his original load specified a 200gr bullet traveling at 1000fps out of a 5" barrel, Norma decided that wasn't enough and ampted it up to 1200fps, the FBI's 10mm Load was a 180gr bullet traveling at 980fps out of a 5" barrel, and the FBI's .40 S&W load ended up being a 180gr bullet traveling at 1050fps out of a 5" barrel. So yeah, the "short n' wimpy" load used by the FBI is actually much closer to Jeff Cooper's specs that the 10mm Normal loads everyone seems to think that Jeff Cooper came up with.

In other words, the FBI didn't really "water down" the 10mm load all that much from it's original specs. Also, as much as folks like to say that the FBI reduced the load solely because agents had trouble with the recoil, it was also because Norma's 10mm load can penetrate deeper than 18" in ballistics gel, which supposedly equates to overpenetration with risk of collateral damage.

There's a reason why full-house, Norma-spec 10mm loads are used by many for self-defense against Polar Bears rather than humans.

 

[Cosmodragoon]

Yep ...

A 'compromise 10mm' without the 10mm's power or accuracy.

The .40's only saving virtue was that you could stuff 12-15 rds into a 9mm-sized gun and hope to please the wee-handed folks.

Except it didn't.

The same whiners who complained that an large-framed 10mm pistol was too big or heavy for all-day carry, almost immediately started whining that the smaller .40 pistol was 'too snappy' for their wuddle hands.

So good riddance. I say ...

Can't handle a 10mm or .45? Fine, no problem. The 9-minimeter is still around and available in the more diminutive pistols.

This is overly broad. As I mentioned previously, I found the recoil of .40 S&W unpleasant in small CCW guns like the Shield. However, it wasn't a big deal in full-sized firearms that better distribute the recoil. It's like a smaller-scale version of .357 magnum in alloy snubs versus full-sized steel revolvers. There is a price to be paid in putting a more powerful cartridge in a smaller gun. Sidestepping the statistical arguments and a philosophical discussion on the limits of our knowledge; we get to decide if the increased power is worth that cost.

Personally, I say "no" in the tiny guns where the cost is maximized and the gain is minimized. I tend to say "yes" with full-sized guns where the opposite may be true.

Now, capacity is another issue. This is a place where .45 really suffers. To get 14 or 15 rounds of .45 acp requires a very large handgun like the FNX-45. I feel like the .40 does okay with 14 or 15 rounds in what we'd normally consider a full-sized handgun. The 9mm might get 17 rounds or so at that size but that's a relatively small difference. At 15 versus 12 rounds, the difference feels more substantial. Below that, we're usually talking about guns that are too small to be comfortable for .40 S&W in the first place.

Now, if you want to talk about more powerful loads in 10mm, I'm going to save that for long-slide models while I'm walking around the woods. The same goes for full-sized longer-barreled revolvers in .357 magnum.

 

[JohnKSa]

No one has shown, by the parameters that you ask for, that there is a "practical difference" between the 38 Spl. and the 357 magnum in an actual gunfight. By the parameters that you want no one can or has shown that there is a difference between the 45 Colt or the 38 Spl. in a real world gunfight. That is because the parameters you ask for are without practical meaning or way of being measured.

The parameters definitely have practical meaning.

The goal of every defender is to stop an attack as rapidly as possible. How could that over-arching goal not have practical meaning? Time can be easily measured, as can the number of shots fired.

So the things I'm talking about are very easily measured and very obviously have practical meaning.

The reason that nobody can provide any evidence is that the differences due to terminal ballistics are undetectable in the data. It's not that nobody cares about how fast an attacker can be neutralized or how many shots it takes--EVERYONE cares about that. The problem is that when you look at the data, there's just nothing in it that shows that the terminal ballistic differences that result from picking one service caliber over another have any effect on the outcome that can be detected.

It's really very simple. A difference can't be big enough to be practically significant and yet still be undetectable. By definition, if you can't tell that there's a difference, it can't be a practically significant difference.

Imagine trying to sell someone something for more than what it's worth by using the rationale that there's a real difference between your product and other apparently identical products but that no one can detect the difference.

My position is simple..."Bring enough gun". Bring a better bullet with a better load. When possible use more power, sometimes that's a better load and bullet sometimes a larger caliber, it's more likely results will go your way.

But that's just it. No one has any evidence that results are any more likely to go your way. The differences due to terminal effect amongst the service pistol calibers can't be shown to have a practically significant effect on the outcome of gunfights.

Why trade away things that are easily shown to make a difference in gunfights for something that no one can prove makes a difference?

Again, if you only care about power, energy, diameter, mass, etc. then make your choice based on those and be happy.

The problem comes when you claim that your choices will give you an advantage in a gunfight--because there's no evidence to support that claim. We can go round and round on this (and we have) but the bottom line is that it just doesn't exist.

Where we agree is that the shooter should choose a gun that they shoot well with good ammo matched to the task they have the gun for. That a well placed shot makes the difference. That caliber or power is less important than shot placement, accuracy and speed.

Close. I would go farther and say that when choosing within the service pistol performance class, terminal ballistics differences due to caliber aren't just "less important", no one has any evidence that they make any practically significant difference at all in how fast attackers or neutralized or how many shots it takes to effect that goal.

 

[Cosmodragoon]

JohnKSa, as soon as we find an ethical way to establish controlled testing on human aggressors with carefully measured data on shots to non-vital but potentially attack-stopping areas such as muscle, bone, connective tissue, etc. where an actual difference might be possible; we'll get you those statistics.

Until then, I think it's reasonable to say "maybe", there might be a little difference under certain conditions. I know we won't really know until we get those stats but who knows? If we put that on a scale against very careful measurements of exactly how much accuracy or speed you lose in exchange on a particular platform, at least for those non-entangled gun fights where that matters, we all might be surprised by the results.

 

[JohnKSa]

...as soon as we find an...we'll get you those statistics.

Again, this isn't complicated and it's not a matter of insufficient data. It's really simple and there's LOTS of data. The problem is that when you look at the data, the evidence that you can improve your chances of winning a gunfight based on terminal ballistic differences resulting from choice within the service pistol class terminal effect can't be detected.

Researchers have access to thousands of real-world shootings with calibers in the service pistol class. If there were a practically significant difference in outcome due to terminal ballistics differences in the class, then how come no one has been able to detect it?

Conversely, given the reality no one has been able to use real-world shooting data to show that one caliber in the service pistol class is superior due to terminal ballistics differences, how could it be possible that it provides a practically significant advantage?

Even if we accept that the difference is there, it's just really hard to detect, if it is so small that it can't be proven to make a difference in thousands of shootings how could it possibly compete with really easily measured and important things like improved accuracy, more rapid recoil recovery, etc.?

 

[Forte S+W]

My issue with the argument that all current duty cartridges are more or less equal is that the organizations who performed the testing which supposedly reached that conclusion haven't really disclosed any in-depth information regarding the parameters of said testing.

Don't get me wrong, I'm sure that their findings are legitimate, but due to their lack of specifics, folks have taken their blanket statements and ran with them, often far past the point of reason. (I once saw a guy make the argument that a Standard Pressure 115gr 9mm FMJ is equally effective as a 230gr .45 ACP +P JHP based on such statements.) Can 9mm Luger be equally as effective to .40 S&W, .45 ACP, and .357 SIG? Sure, but in what loading? We already know that Law Enforcement doesn't use Standard Pressure 9mm loads, nor does the Military, ergo the blanket statement that 9mm Luger is equally effective to other duty cartridges is misleading considering that said statement doesn't apply to Standard Pressure ammo.

Furthermore, considering that 9mm Luger is less expensive than other duty cartridges, it's all the more difficult to take such statements at face value, because while they claim that part of their reason to switch to 9mm Luger is because it's more easy to shoot with than .40 S&W, is that honestly true of whatever 9mm load they're using? Because assuming they're using some turbo-charged 125gr +P+ load that essentially turns 9mm into .357 SIG, that statement is likely false. (Can't be sure though, seeing as I've never shot any 9mm +P+ loads, but I'm fairly confident that they aren't any more manageable than .40 S&W considering that even +P loads are substantially higher in pressure that .40cal.)

Last but not least, folks seem to forget that such testing was performed specifically around the concept of human combatants, ergo while a 125gr 9mm Luger +P+ JHP may be equal to a 230gr Standard Pressure .45 ACP against a human, that doesn't necessarily mean that it would be as affective against predatory animals. Yet still you'll see folks in threads on outdoor forums making ignorant posts about how their Glock 19 is just as good as a Glock 40 or better than a Ruger Redhawk because; "the FBI says 9mm just as good!"

 

[Cosmodragoon]

Again, this isn't complicated and it's not a matter of insufficient data. It's really simple and there's LOTS of data. The problem is that when you look at the data, the evidence that you can improve your chances of winning a gunfight based on terminal ballistic differences resulting from choice within the service pistol class terminal effect can't be detected.

Researchers have access to thousands of real-world shootings with calibers in the service pistol class. If there were a practically significant difference in outcome due to terminal ballistics differences in the class, then how come no one has been able to detect it?

Conversely, given the reality no one has been able to use real-world shooting data to show that one caliber in the service pistol class is superior due to terminal ballistics differences, how could it be possible that it provides a practically significant advantage?

Even if we accept that the difference is there, it's just really hard to detect, if it is so small that it can't be proven to make a difference in thousands of shootings how could it possibly compete with really easily measured and important things like improved accuracy, more rapid recoil recovery, etc.?

You keep saying that compared to all the recorded shootings, there is no detectable difference. An important point is that of all those recorded shootings, "the data" isn't necessarily great. This massive body of evidence you keep referring to is not uniform and is much more sparse on accurate details than I think you might be taking it to be.

One feature of that is that two important subclasses of shootings I've discussed are not readily isolable from that body of existing data. The first is statistics for all non-vital hits that stopped an attack, including location of the shot, how long it took, etc. Do we even have those numbers available to talk about? (This is why I've had to discuss it in terms of logical assumption and thought experiment, as opposed to probability from existing statistics.)

The second is the subclass of shootings where your trade-off costs in speed and accuracy are rendered meaningless by distance or entanglement. For instance, assuming that you lose enough speed and accuracy on a particular platform between 9mm and .40 S&W to be significant in the first place, that will only apply to those situations in which that difference contributes to the outcome. For instance, it could matter under a bunch of conditions such as an attacker charging you from seven yards, defending yourself around the isles of a convenience store, etc. However, it is unlikely to matter under conditions of very close attackers, entangled fights, etc.

 

[fastbolt]

Lots of angst about something that's not really even a molehill in the field of service/defensive caliber usage and application.

The 9mm was pronounced to be "done" when the .40 arrived. Except it wasn't done.

Now the 9mm has enjoyed somewhat of a resurgence among LE agency users, for reasons that have openly been reported to primarily have more to with training and equipment (maintenance) issues than anything else. One of the biggest influences has been the time and cost involved to train hundreds or thousands of new users who aren't exactly gun enthusiasts.

Well, hell, that was something we saw in LE in revolver days, when more agencies chose .38SPL than .357MAG. The .38SPl was also given a boost when the +P (and later the +P+) .38 loads arrived. That didn't mean .357MAG wasn't still chosen (or allowed) by agencies who liked the somewhat faster moving caliber, though.

Still lots of satisfied .40 users to be found in LE, too. The largest state agency (CHP) in the nation elected to remain using .40 when they finally migrated from metal to plastic weapons.

Even .45ACP has been enjoying a continued presence, after yet another of the cyclical periods of renewed interest in the venerable caliber.

FWIW (not much), today I'm going down to renew my LEOSA with pistols and revolver. I'll be using one of my Airweights (assorted standard pressure and +P loads) and my G27. Why the G27? Because I just replaced the old Mepro NS with some never-used Ameriglo FBI-contract type NS a friend gave me. I want to confirm POA/POI using it for a qual. I loaded several mags with some "recycled" carry rounds. As I was grabbing loose rounds from one of my "range ammo boxes", stuffing mags, I noted that I was mixing some 180gr HST, a couple production vintages of 180gr RA40T (and some 165gr RA40TA, it appeared), Rem 180gr GS and even a couple of remaining Rem 180gr Express, W-W 180gr RA40180HP ... and a single round of W-W 155gr STHP (which I only bought for my 4040PD, as it really likes that load).

In other words, mostly the stuff I was formerly issued as duty ammo at various times over the years, as well as the STHP I picked up for the 4040.

One consistent thing I've noted over the years I served as a LE firearms instructor and working cop was that the more I shot my .40's, the better I shot my 9's.

Round and round it goes.

 

[nanney1]

Aren’t a lot of competition shooters using 40 to make power factor?

Every time I go to shoot USPSA, plenty of shooters in Limited class using .40 S&W pistols to make major power factor.

 

[Alert]

I just fairly recently got a Glock model 22 and two 22 round Glock magazines at a deal I couldn’t pass up

 

[JohnKSa]

You keep saying that compared to all the recorded shootings, there is no detectable difference. An important point is that of all those recorded shootings, "the data" isn't necessarily great. This massive body of evidence you keep referring to is not uniform and is much more sparse on accurate details than I think you might be taking it to be.

One feature of that is that two important subclasses of shootings I've discussed are not readily isolable from that body of existing data. The first is statistics for all non-vital hits that stopped an attack, including location of the shot, how long it took, etc. Do we even have those numbers available to talk about? (This is why I've had to discuss it in terms of logical assumption and thought experiment, as opposed to probability from existing statistics.)

These are all just reasons for why no one can prove the difference exists. Again, if it's so hard to show that it exists that no one can do it (regardless of the many reasons why that might be true) how can it be practically significant?

By definition, if it made a practically significant, people would be able to detect a difference in outcomes of real-world gunfights. The inability to detect that it makes a difference is exactly equivalent to saying that it doesn't make a practically significant difference.

The second is the subclass of shootings where your trade-off costs in speed and accuracy are rendered meaningless by distance or entanglement. For instance, assuming that you lose enough speed and accuracy on a particular platform between 9mm and .40 S&W to be significant in the first place, that will only apply to those situations in which that difference contributes to the outcome. For instance, it could matter under a bunch of conditions such as an attacker charging you from seven yards, defending yourself around the isles of a convenience store, etc. However, it is unlikely to matter under conditions of very close attackers, entangled fights, etc.

Yes, there are clearly gunfights where speed and accuracy don't matter. If you're rolling around on the ground fighting with someone, recoil recovery and accuracy probably won't play a decisive part in the outcome. Capacity still might, however.

I suppose it is possible to construct a reasonable argument that there are some gunfights in which nothing related to caliber choice within the service pistol class matters at all. That's worth thinking about, but I don't see how such an argument could be used to build up one caliber in the class at the expense of another--or to try to make the point that one is obviously inferior given that the premise is that in certain cases nothing about caliber choice makes any difference at all. i.e. That they all provide exactly the same level of effectiveness (or ineffectiveness) in certain cases.

 

[amd6547]

I don’t care if the one shot effectiveness is improved by one tenth one percent...I’ll take it.

 

[Cosmodragoon]

JohnKSa wrote:

These are all just reasons for why no one can prove the difference exists. Again, if it's so hard to show that it exists that no one can do it (regardless of the many reasons why that might be true) how can it be practically significant?

I have illustrated how it could be practically significant, in some particular types of cases. That's the key here.

The point is that (1) the argument that there is definitely no difference in all cases is dubious and (2) cannot be adequately supported by the existing evidence.

I think it is safe to say that choice in mainstream defensive caliber for handguns won't make much difference in a lot of cases. "Most" could be argued. Just be wary of "all".

By that same token, I don't think there is a blanket "best" choice that applies universally for everyone in every situation. I think some choices will be better for certain people under certain conditions in certain types of situation. So we get to think about our individual circumstances and make some bets based on our understanding of the probabilities. That's really what we are doing for any kind of preparedness.