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uz2bUSMC
09-04-2012, 15:00
Here's a link to a resent article on BPW. Some of you may know what the acronym stands for. Some of you may have never seen any formal information regarding this subject, so it is here for you to view if you care to. This usually brings on a passionate debate, however, information in whatever form is usually good to have. This is something I personally consider as an "addition" to load choice criteria (BPW). Some hate this topic, some find it interesting... either way, here is a sample reading.

http://arxiv.org/ftp/arxiv/papers/1105/1105.4738.pdf

ABNAK
09-04-2012, 16:46
Ya know, I've been a believer in the BPW theory years ago when speed was the only thing that made bullets function well. That gave you a credible BPW from the sheer velocity and a mushrooming (even fragging a little sometimes) bullet.

Then I got caught up in the modern bullet design line of thinking. HST is a perfect example, especially in it's heavy-for-caliber loadings. Slower speeds, yes.......but near perfect expansion and penetration. Best of both worlds, right? Low recoil yielding faster follow-up shots but textbook terminal performance.

As of late (and I mean the last few weeks) I'm gravitating again towards the "velocity uber alles" theme. I've put my well-worn and trusty Glock 19 and 147gr +P HST's in the safe and broke out the Glock 23 with 357Sig barrel for IWB CCW. Loading it with 125gr Sierra JHP's from DoubleTap which I've personally clocked at an average of 1452fps. Yeah, they might frag a bit but so did the vaunted .357 Magnum, and with that velocity and bullet weight it should nicely mimic that famous round.

I guess the closer you can make a handgun to a rifle (albeit still nowhere near but moving in that general direction) the better off you'll be, given proper shot placement and practice.

YMMV. :dunno:

uz2bUSMC
09-04-2012, 17:04
I guess the closer you can make a handgun to a rifle (albeit still nowhere near but moving in that general direction) the better off you'll be, given proper shot placement and practice.

YMMV. :dunno:

Well, looking at rate of transfer of energy, bullet construction plays a huge part. A rifle has more potential but it doesn't automatically mean it will always be better than a pistol. If you are using a tough rifle bullet that will not expand quick enough in a human body, the transfer of energy will be slower and mostly wasted after it exits and continues on it's way. A .357 sig may actually transfer energy more rapidly as it comes to a stop after only 12", as an example.

M 7
09-04-2012, 23:25
Greetings,

Thanks for the link.

It was interesting, but I'm not sure there is much value in the phenomenon.

Since few of us are able to conceal rifles, I fail to see the value, let alone the relevance, of "qualitative results" taken from shooting a few deer with a rifle that fires a 6.5mm, 85 gr. bullet at 3115 fps as opposed to the service calibers that most of us are constrained to carry in our defense that produce velocities of no more than about 1400 fps.

The author's own reported results portray significant inconsistencies even at these high velocities- these high velocities being the facilitator of the bpw mechanism- e.g: the smallest deer listed @ 49kg demonstrating only capillary damage, the second deer @ 80kg having capillary damage and petechiae on three lobes, and the third deer @ 66kg showing "remarkably greater vascular damage" (whatever that is, the author makes no objective distinction or quantification as to how much "remarkably greater" is) with diffuse petechiae. In the first line of the "Results" section on page 2, the author states, "In each case, no hematomas or large amounts of bleeding were observed in the brain." If the bpw effect is this miniscule and unreliable even at these heightened velocities (approaching one kilometer per second), what's the point?

The author's failure to connect or correlate this effect with any substantial increase in the rate of the test subjects' demise makes the whole proposition appear to be an exercise in diminishing returns. None of the distances covered by the deer after being shot with the 6.5mm rifle (16m, 48m and 59m) was atypical in any way. A more definitive and conclusive result, if bpw was really a significant factor, would've been that at least one, perhaps two (and all three being even moreso), of the deer suffering the greater neuro-vascular trauma collapsed after being shot without taking more than a step or two.

Of even greater concern, the author's sample population of just three deer is wholly insufficient to draw any reasonable statistically supportable correlation. On that count alone, this study stands suspect.

Given the highly unreliable nature of this effect even at such high speeds, is it even worth considering where common handgun service calibers whose bullets rarely, if ever, exceed half the speed of the rifle bullets used in the experiment are involved?

I doubt it.

ADK_40GLKr
09-05-2012, 05:36
BPW="Blast Pressure Wave"?

Hmmmm... Interesting.

ADK_40GLKr
09-05-2012, 05:37
BPW="Blast Pressure Wave"?

Hmmmm... Interesting.

uz2bUSMC
09-05-2012, 05:47
Greetings,

Thanks for the link.

It was interesting, but I'm not sure there is much value in the phenomenon.

Since few of us are able to conceal rifles, I fail to see the value, let alone the relevance, of "qualitative results" taken from shooting a few deer with a rifle that fires a 6.5mm, 85 gr. bullet at 3115 fps as opposed to the service calibers that most of us are constrained to carry in our defense that produce velocities of no more than about 1400 fps.

The author's own reported results portray significant inconsistencies even at these high velocities- these high velocities being the facilitator of the bpw mechanism- e.g: the smallest deer listed @ 49kg demonstrating only capillary damage, the second deer @ 80kg having capillary damage and petechiae on three lobes, and the third deer @ 66kg showing "remarkably greater vascular damage" (whatever that is, the author makes no objective distinction or quantification as to how much "remarkably greater" is) with diffuse petechiae. In the first line of the "Results" section on page 2, the author states, "In each case, no hematomas or large amounts of bleeding were observed in the brain." If the bpw effect is this miniscule and unreliable even at these heightened velocities (approaching one kilometer per second), what's the point?

The author's failure to connect or correlate this effect with any substantial increase in the rate of the test subjects' demise makes the whole proposition appear to be an exercise in diminishing returns. None of the distances covered by the deer after being shot with the 6.5mm rifle (16m, 48m and 59m) was atypical in any way. A more definitive and conclusive result, if bpw was really a significant factor, would've been that at least one, perhaps two (and all three being even moreso), of the deer suffering the greater neuro-vascular trauma collapsed after being shot without taking more than a step or two.

Of even greater concern, the author's sample population of just three deer is wholly insufficient to draw any reasonable statistically supportable correlation. On that count alone, this study stands suspect.

Given the highly unreliable nature of this effect even at such high speeds, is it even worth considering where common handgun service calibers whose bullets rarely, if ever, exceed half the speed of the rifle bullets used in the experiment are involved?

I doubt it.

I'm glad you replied, it seems you are good for these discussions. I have many points in response to your post but it will have to wait till I'm at my comp.

M 7
09-05-2012, 08:43
I'm glad you replied, it seems you are good for these discussions. I have many points in response to your post but it will have to wait till I'm at my comp.

Well, thank you. That's an awfully flattering description of my abilities as I am not sure that I am anywhere near that level.

I tried to keep an open mind while reading the paper, setting aside for the time being, its numerous procedural, logical, and material flaws some of which were addressed above. While there is probably some miniscule effect present, I question the wisdom (and perhaps the sanity? :dunno:) of relying upon such an unreliable mechanism for anything that one's life depends upon, especially with the handgun calibers where this already miniscule effect would be further diminished by the lower velocities and commensurately much lower energies of those bullets.

In the end, I believe that it is better to rely upon the primary quantities of penetration and permanent wound cavity rather than an insignificant tertiary effect that cannot be repeated with any degree of reliability even in the presence of high projectile velocities approaching 1 kmps.

uz2bUSMC
09-05-2012, 16:03
Greetings,

Thanks for the link.

It was interesting, but I'm not sure there is much value in the phenomenon.

-Think added benefit.

Since few of us are able to conceal rifles, I fail to see the value, let alone the relevance, of "qualitative results" taken from shooting a few deer with a rifle that fires a 6.5mm, 85 gr. bullet at 3115 fps as opposed to the service calibers that most of us are constrained to carry in our defense that produce velocities of no more than about 1400 fps.

-All things considered must stay in perspective. The common mantra is that handguns are handguns and rifles are rifles. As you would know, this is not the case. A .500 S&W is certainly rifle strength in a handgun platform and a .22 lr doesn't make for an impressive "rifle". So what is really at the table is terminal performance of a given cartridge regardless of the platform that got it on target.

-Now in keeping perspective, the bullet obviously has many variables that that can allow to achieve better or worse results terminally. Commonly, people wish to gravitate towards one quality or another in a debate such as velocity. Velocity alone is only one piece of the puzzle, bullet construction must also be considered to begin seeing the bigger picture. An 85 grain bullet at 3115fps certainly has the potential, but if the selected projectile does not expand and fails to yaw, the energy transfer will be low and peak BPW will be reduced. A high energy service cartridge loading such as the .357 or 10mm that penetrates 11-12" may impart energy more rapidly causing higher peak BPW than the rifle in this example.

The author's own reported results portray significant inconsistencies even at these high velocities- these high velocities being the facilitator of the bpw mechanism- e.g: the smallest deer listed @ 49kg demonstrating only capillary damage, the second deer @ 80kg having capillary damage and petechiae on three lobes, and the third deer @ 66kg showing "remarkably greater vascular damage" (whatever that is, the author makes no objective distinction or quantification as to how much "remarkably greater" is) with diffuse petechiae. In the first line of the "Results" section on page 2, the author states, "In each case, no hematomas or large amounts of bleeding were observed in the brain." If the bpw effect is this minuscule and unreliable even at these heightened velocities (approaching one kilometer per second), what's the point?

-The point? Faster incapacitation. We know that a permanent crush cavity through the vitals will cause blood loss, drop in blood pressure leading to incapacitation and then eventual death. We also know that a phenomena exists that allows animals and humans to drop on the spot without a direct CNS hit. Stopping fast enough to rule out psychological aspects as the brain has not had enough time to process. Choosing a loading that meets your needs based on your individual risk assessment and produces high BPW can only be a benefit. Remote trauma to the brain is not minuscule at the level achieved in this test, IMHO. Any remote trauma at this level could be the switch that puts assailants down fast. And again, heightened velocity and bullet construction together is the important factor.

The author's failure to connect or correlate this effect with any substantial increase in the rate of the test subjects' demise makes the whole proposition appear to be an exercise in diminishing returns. None of the distances covered by the deer after being shot with the 6.5mm rifle (16m, 48m and 59m) was atypical in any way. A more definitive and conclusive result, if bpw was really a significant factor, would've been that at least one, perhaps two (and all three being even moreso), of the deer suffering the greater neuro-vascular trauma collapsed after being shot without taking more than a step or two.

-First, the author has stated in the past that BPW is not 100%. Second, what this test shows is that (although a small sample) a shot placed cosest to the plumbing has greater effect (16m travel). I should have mentioned this earlier actually. The heart being struck directly, probably at peak pressure, would create the greatest amount of pressure wave transfer though vessels. Also, in general, impact locations closer to the head will yield higher pressure since the wave is strongest at it's point of origin. Something you would know better than I since you seem to be very educated.

Of even greater concern, the author's sample population of just three deer is wholly insufficient to draw any reasonable statistically supportable correlation. On that count alone, this study stands suspect.

-There is also the correlation to 33 mentioned autopsies as-well as other tests conducted on deer. And the correlation between BABT and TBI.

Given the highly unreliable nature of this effect even at such high speeds, is it even worth considering where common handgun service calibers whose bullets rarely, if ever, exceed half the speed of the rifle bullets used in the experiment are involved?

-Is it even worth considering? Yes. This is where these debates often run off course. BPW should not be your first consideration when choosing a cartridge. BPW is not 100%. As with any round selection, it should be chosen based on your needs. If you go by F.B.I. protocol, so be it. Once you have chosen your criteria and several loadings meet your needs, why not choose one with higher BPW?? Maybe a 9+p+ and a .357 round fall into that category with near identical penetration with the sig leading in energy by about 100 ft.lbs... if you are not bothered by difference in follow up shots... why not choose the sig?

I doubt it.

That is just the quick run down on my views, hopefully we can discuss further.

M 7
09-05-2012, 17:27
That is just the quick run down on my views, hopefully we can discuss further.

Sure, I'll do my best.

-Think added benefit.

I hope that you'll take no offense, but I think that you are trying to make a silk purse from a sow's ear. :)

Even at speeds in excess of 3000 fps, the benefit of bpw (bpw being highly dependent upon the speed of the bullet) is miniscule at best. Even then, this is of no value to the average gun carrier since they rarely have occasion to carry long guns and the velocities necessary to achieve even a modest effect are not attainable in any conveniently portable and concealable handgun.

-First, the author has stated in the past that BPW is not 100%. Second, what this test shows is that (although a small sample) a shot placed cosest to the plumbing has greater effect (16m travel).

Rough water here. :cool:

One data point, let alone three, is not a statistically valid sample population. Yes, that particular deer only went 16m after being shot, but due to the fact that there was no other data point that matched or came close to that one point, it is impossible to say whether it was confirmation of the effect or due to the effect of some other confounding factor. This is one of the inherent problems with insufficiently large test populations.

-There is also the correlation to 33 mentioned autopsies as-well as other tests conducted on deer. And the correlation between BABT and TBI.

This hits upon one of the biggest problems the scientific research community has with extremely small test populations. There might be a correlation, but it is impossible to say authoritatively that there is a correlation since we are dealing with such small test populations- even with the aggregate test population that you suggested earlier.

We are addressing a very minute, highly unreliable effect that arises from the interaction of a bullet within a highly variable, stochastic (random) medium (animal bodies) from a perspective produced within a test population measuring, at most, in the tens of subjects. Because of the huge physiological and anatomical variables that have been introduced through the use of living creatures as test subjects (deer are simply not "standardizable"), the number of test subjects necessary to eliminate these factors' influence would likely be in the hundreds of thousands and more probably in the millions, if not tens of millions. Even if the aggregate population that you have suggested were composed of several thousand data points, it is still several orders of magnitude (one magnitude is a factor of ten) below what it would need to be in order to exclude the confounding factors that have just been addressed.

This leaves us not only with bpw being a "definite maybe", but also with no way of saying with any certainty just "how big" that "definite maybe" is. If the effect is unreliable and imperceptible, it is of little practical value to the vast majority of gun carriers and therefore nothing more than a mere scientific curiosity.

To read more than there is into these extremely limited studies amounts to nothing more than chasing rainbows.

Of course, we can always take this study's conclusions on faith instead of substantiated proof. Nothing wrong with that, but it is very important not to confuse the former with the latter. :winkie:

:)

uz2bUSMC
09-05-2012, 17:51
Sure, I'll do my best.



I hope that you'll take no offense, but I think that you are trying to make a silk purse from a sow's ear. :)

Even at speeds in excess of 3000 fps, the benefit of bpw (bpw being highly dependent upon the speed of the bullet) is minuscule at best. Even then, this is of no value to the average gun carrier since they rarely have occasion to carry long guns and the velocities necessary to achieve even a modest effect are not attainable in any conveniently portable and concealable handgun.



Rough water here. :cool:

One data point, let alone three, is not a statistically valid sample population. Yes, that particular deer only went 16m after being shot, but due to the fact that there was no other data point that matched or came close to that one point, it is impossible to say whether it was confirmation of the effect or due to the effect of some other confounding factor. This is one of the inherent problems with insufficiently large test populations.



This hits upon one of the biggest problems the scientific research community has with extremely small test populations. There might be a correlation, but it is impossible to say authoritatively that there is a correlation since we are dealing with such small test populations- even with the aggregate test population that you suggested earlier.

We are addressing a very minute, highly unreliable effect that arises from the interaction of a bullet within a highly variable, stochastic (random) medium (animal bodies) from a perspective produced within a test population measuring, at most, in the tens of subjects. Because of the huge physiological and anatomical variables that have been introduced through the use of living creatures as test subjects (deer are simply not "standardizable"), the number of test subjects necessary to eliminate these factors' influence would likely be in the hundreds of thousands and more probably in the millions, if not tens of millions. Even if the aggregate population that you have suggested were composed of several thousand data points, it is still several orders of magnitude (one magnitude is a factor of ten) below what it would need to be in order to exclude the confounding factors that have just been addressed.

This leaves us not only with bpw being a "definite maybe", but also with no way of saying with any certainty just "how big" that "definite maybe" is. If the effect is imperceptible, it is of little value to the vast majority of gun carriers and therefore nothing more than a mere scientific curiosity.

To read more than there is into these extremely limited studies amounts to nothing more than chasing rainbows.

Of course, we can always take this study's conclusions on faith instead of substantiated proof. Nothing wrong with that, but it is very important not to confuse the former with the latter. :winkie:

:)

I knew you would came outta your shell and talk like the days of old.:whistling: But, this is where the horse gets beat some more. Velocity alone is not the end all, although I see it was mentioned again as the only factor. I just don't feel like playing that game. Anyhow, until your IWBA buddies can explain what drops a person (or animal) in there tracks before psychological factors can be claimed, I'll refrain from partaking in the koolaid. Nothing has changed with my views. Hope all is well with you.:wavey:

I'll be continuing but don't take offense if I don't really want to push further on the subject with you. The repetition of the Fackler mantra is not enough. I also can't allow things that the Facklerites simply "say" to be misconstrued as "fact" because it is simply being said. Some here haven't noticed the difference. Talk to you later, buddy.

M 7
09-05-2012, 18:03
I knew you would came outta your shell and talk like the days of old.:whistling: But, this is where the horse gets beat some more. Velocity alone is not the end all, although I see it was mentioned again as the only factor. I just don't feel like playing that game. Anyhow, until your IWBA buddies can explain what drops a person (or animal) in there tracks before psychological factors can be claimed, I'll refrain from partaking in the koolaid. Nothing has changed with my views. Hope all is well with you.:wavey:

I'll be continuing but don't take offense if I don't really want to push further on the subject with you. The repetition of the Fackler mantra is not enough. I also can't allow things that the Facklerites simply "say" to be misconstrued as "fact" because it is simply being said. Some here haven't noticed the difference. Talk to you later, buddy.

I have no idea what you are talking about, but it's clear that you've taken offense at what I've said- that's unfortunate since none was intended. I was under the impression that we were exchanging ideas in a respectful manner.

Since it's come to this, I'll simply wish you the best. :)

Tiro Fijo
09-05-2012, 19:45
Newsflash: every few months this controversial topic arises and all it does is irritate both sides. Vitriolic rhetoric ensues and in the end no one is convinced of the veracity of the other point of view as both are deeply entrenched in their Weltanschauung. It descends into endless bickering and childish ranting with several people even having been banned over it.


Guess where this is headed? :upeyes:

ChiefWPD
09-05-2012, 20:15
Newsflash: every few months this controversial topic arises and all it does is irritate both sides. Vitriolic rhetoric ensues and in the end no one is convinced of the veracity of the other point of view as both are deeply entrenched in their Weltanschauung. It descends into endless bickering and childish ranting with several people even having been banned over it.


Guess where this is headed? :upeyes:

I agree. Becoming embroiled in a discussion regarding which round/caliber/projectile/velocity combination is more effective over any other is a recipe for acrimonious debate. Funny thing is, this subject was one of the lectures I gave (titled Bullet Potential) while serving as a sgt and lt with the NYPD Firearms and Tactics Section and conducting the NYPD Police Firearms Instructors School.

Before having that assignment I spent twelve years as a detective, including as a homicide detective. The inconsistencies of what firearms rounds do to both the human body as well as how the human body reacts to being impacted by these rounds would boggle the mind.

So, as mentioned a moment ago, Iíll sit this one out.

:wavey: