Ballistic gelatin comparisons: Part I

[Tokarev]

https://www.policeone.com/police-products/firearms/accessories/ammunition/articles/ballistic-gelatin-comparisons-part-i-ndmFBGUHw79F9s0a/?utm_source=PoliceOne+Member+Newsletter&utm_campaign=f3d49dffb8-EMAIL_CAMPAIGN_2019_11_12_09_31&utm_medium=email&utm_term=0_ca044a84ea-f3d49dffb8-42778711

Sent from my SM-G930P using Tapatalk

[CZ Man]

Looking forward to reading the results.

[Balisong]

WTF??? I read through all of that just to see no data provided in the "article"? I want to see where this goes, but the hell kind of journalism is that?

[the Schwartz]

WTF??? I read through all of that just to see no data provided in the "article"? I want to see where this goes, but the hell kind of journalism is that?

Of course there is no data, because it is not an honest journalistic piece. It's most likely nothing more than a marketing campaign being offered as journalism.

The pressure that drives the expansion of bullets—like JHPs—is expressed by the Bernoulli pressure equation; P = ½ρV². As can be seen in the relatively simple Bernoulli pressure equation, pressure is dictated by two factors, those being the velocity, V, of the flow field relative to the projectile passing through it, and the mass density, ρ, of the test medium expressed in terms of mass per unit volume—usually as grams/centimeter³ or kilograms/meter³. For any specific projectile velocity, V, the pressure produced by identical projectiles having the same drag coefficient varies only according to the mass density of the test medium being traversed. If the mass density of a test medium (e.g.: 10% ordnance gelatin, water, etc.) differs significantly from that of soft tissue (that is, 1.020 — 1.060 grams/centimeter³) being physically modeled, then expansion and penetration depth data obtained in that medium will not correctly represent the expansion and penetration depth that occurs in actual soft tissue.

Compared to the mass density of 10% concentration ordnance gelatin (which is ρ = 1.040 ± 0.020 grams/centimeter³), the mass density of Clear Ballistics Gelatin is 0.824 grams/centimeter³* which means that the pressure produced during all phases of the projectile's penetration through it will be on the order of 19.2% — 22.3% less than that occurring in either properly prepared 10% ordnance gelatin and/or human soft tissue analog (e.g.: usu. porcine thigh muscle tissue; 40 kg. pig). This means that projectile expansion will be less and that resultant penetration depth will be greater than that seen in 10% ordnance gelatin test medium.

John Ervin, Mech. Eng. has a video here—

https://www.youtube.com/watch?v=5pqPBnSYTIc&feature=emb_logo

—that compares the diminished expansion diameters and resulting increased penetration depth that occur in the clear, synthetic gelatin as opposed to 10% ordnance gelatin.

At 18:45 in the linked video, Ervin provides a tabulated comparison of BB validation depths obtained in both 10% ordnance gelatin and the clear, synthetic gelatin test mediums.

44759

The 10% ordnance gelatin passes the BB validation test confirming that it produces the correct shear response and will represent penetration depth correctly. The clear, synthetic gelatin does not pass the BB validation test and fails to produce the correct shear response meaning that it will not represent terminal penetration depth correctly.

Ervin also has an entire webpage dedicated to comparing test data (expansion and penetration depth) obtained in both mediums here:

http://www.brassfetcher.com/Synthetic%20Gelatin/Synthetic%20Gelatin.html

No single, simple, linear value for converting test results obtained in the clear, synthetic gelatin for comparison to those obtained in 10% ordnance gelatin is found to exist.

If I've missed something, I am sure that Dr. Roberts can remedy any over-sight.

*In the BrassFetcher webpage that compares test data obtained in both mediums, Ervin reports the mass density of the clear, synthetic gelatin as being 790 kilograms/meter³ which is equivalent to 0.790 grams/centimeter³ which is less than the quoted mass density of 0.824 grams/centimeter³ found in other literature as seen below.

ETA: Additional documentation of test result discrepancies for expansion and penetration depths in the high-velocity regime in both test mediums can be found here: https://web.archive.org/web/20140216104148/http://www.brassfetcher.com/223%20Remington/Clear%20Ballistics.pdf

[0ddl0t]

Of course there is no data, because it is not an honest journalistic piece. It's most likely nothing more than a marketing campaign being offered as journalism.
This was just part 1. I'm betting the data will be in part 3


If the mass density of a test medium (e.g.: 10% ordnance gelatin, water, etc.) differs significantly from that of soft tissue (that is, 1.020 — 1.060 grams/centimeter³) being physically modeled, then expansion and penetration depth data obtained in that medium will not correctly represent the expansion and penetration depth that occurs in actual soft tissue.

Granted, but a bullet might perform well in 10% ordinance gelatin yet fail to expand in fat (~ 0.9 g/cm^3). So while I understand the desire to compare penetration & expansion numbers across tests using identical media, I'd also like the bullet to have a robust design that allows it to reliably expand no matter how obese or muscular (~1.06 g/cm^3) the assailant is...

[Balisong]

Schwartz, thank you for that awesome write-up!

[the Schwartz]

This was just part 1. I'm betting the data will be in part 3

Granted, but a bullet might perform well in 10% ordinance gelatin yet fail to expand in fat (~ 0.9 g/cm^3). So while I understand the desire to compare penetration & expansion numbers across tests using identical media, I'd also like the bullet to have a robust design that allows it to reliably expand no matter how obese or muscular (~1.06 g/cm^3) the assailant is...

According to this source: https://www.ncbi.nlm.nih.gov/pubmed/8148928 —

—whole body (human) adipose tissue density ranges from 0.925-0.970 grams/centimeter³ and is more closely represented in terms of density related pressure effects by both 10% ordnance gelatin (ρ = 1.040 ± 0.020 grams/centimeter³) and water (ρ = 0.991625 ± 0.0041225 grams/centimeter³). Given the smaller difference between the mass density of whole body adipose tissue and these two test mediums (namely, 10% ordnance gelatin and water) it is hard to see any benefit offered by the use of the clear, synthetic gelatin which has a much lower mass density somewhere between 0.790 and 0.824 grams/centimeter³ over 10% ordnance gelatin or water.

Averaged differences in mass density of test mediums and whole body adipose tissue:

whole body adipose tissue: (0.950 ± 0.050 grams/centimeter³)

Water, having a density of 0.991625 ± 0.0041225 grams/centimeter³, is 4.38% denser than adipose tissue with an average difference of 0.041625 grams/centimeter³
10% ordnance gelatin: 1.040 ± 0.020 grams/centimeter³ is 9.47% denser than adipose tissue with an average difference of 0.090 grams/centimeter³
clear, synthetic gelatin: 0.807 ± 0.017 grams/centimeter³ is 15.05% less dense than adipose tissue with an average difference of 0.143 grams/centimeter³

Over the course of its use as a valid, repeatable terminal ballistic test medium, 10% ordnance gelatin has adequately represented the aggregate average density of the all of the tissues found in the human body, which ranges from very low density tissues like lung tissue (values obtained for the density of the upper, middle, and lower lung were 0.123 ± 0.46 g/cm³, 0.121 ± 0.033, and 0.154 ± 0.057 g/cm³ during inspiration and were 0.215 ± 0.058 g/cm³, 0.228 ± 0.066, and 0.260 ± 0.078 g/cm³ during expiration, respectively) [ https://www.ncbi.nlm.nih.gov/pubmed/2630782/] ] all the way to the mineral density of bone which ranges from 700 - 800 g/cm² in the human forearm to 1,000 - 1,200 g/cm² the human spinal column.

Further, as Dr. Roberts has stated in a prior post here—


A very close correlation between actual shootings and properly performed laboratory testing has been demonstrated for at least three decades now. In most properly conducted post-mortem evaluations, there is indeed a rough 1:1 ratio between gel and torso tissue––for example, Gene Wolberg's study of nearly 150 SDPD OIS incidents showed the majority of the 9mm 147 gr bullets fired by officers had penetrated about 13" and expanded between 0.60 to 0.62 inches in both human tissue and 10% ordnance gelatin. While there was a greater range of results in human tissue than in gel, the averages were nearly identical. Several other agencies with strong, scientifically based ammunition terminal performance testing programs have conducted similar reviews of their shooting incidents with much the same results––there is an extremely strong connection between properly conducted and interpreted 10% ordnance gelatin laboratory studies and the physiological effects of projectiles in actual shooting incidents. You just have to understand the anatomy and variables involved while making an evaluation. Note that projectiles from many real world shootings tend to behave like those in four layer denim testing.

—I'd take this:


"there is indeed a rough 1:1 ratio between gel and torso tissue"

—as the final authoritative word on the suitability (in all respects) of 10% ordnance gelatin as a terminal ballistic test medium and its ability to represent the effects of the varying densities of the tissues found in the human body.

[the Schwartz]

Schwartz, thank you for that awesome write-up!

You are welcome.

[0ddl0t]

Over the course of its use as a valid, repeatable terminal ballistic test medium, 10% ordnance gelatin has adequately represented the aggregate average density of the all of the tissues found in the human body

And in the aggregate, that's true. But near the boundaries of barrel length and bullet weight, testing solely in 10% OG has its flaws.

Take 147 grain gold dots fired from a 3" barrel through heavy denim. They will perform fine in 10% ordnance gelatin, but completely fail to expand about half the time in clear gel. On the other hand, 147 grain HSTs perform well in both media. Which round would you load in your P365/PM9/Shield/LC9 (especially if you live in an area with an obesity epidemic)?

[the Schwartz]

And in the aggregate, that's true. But near the boundaries of barrel length and bullet weight, testing solely in 10% OG has its flaws.

Take 147 grain gold dots fired from a 3" barrel through heavy denim. They will perform fine in 10% ordnance gelatin, but completely fail to expand about half the time in clear gel. On the other hand, 147 grain HSTs perform well in both media. Which round would you load in your P365/PM9/Shield/LC9 (especially if you live in an area with an obesity epidemic)?

I would choose either of the designs based upon their performance in the 10% ordnance gelatin and/or in water. Both of these tissue analogs have long histories as valid terminal ballistic test mediums.

The video above (provided here again)—

https://www.youtube.com/watch?v=5pqPBnSYTIc&feature=emb_logo

—demonstrates without question that the clear, synthetic gel lacks the proper shear response which results in the under representation of projectile expansion and the over representation of penetration depth in ways that are neither predictable nor directly convertible (through the use of a constant conversion value) to values seen in the other proven mediums or in soft tissue including adipose tissue.

Others have also found similar deficiencies in the performance of the clear, synthetic gel, too: https://www.youtube.com/watch?time_continue=23&v=xJF-C2wuuCI&feature=emb_logo

Why place blame on any bullet design for its performance in an inconsistent* test medium that has no proven/known representative equivalence to living tissue?

The issue has been addressed adequately here—


Also, despite much ill-informed You-Tube comments to the contrary, there is NO such thing as "FBI spec Clear Gel blocks"; to the best of my knowledge, NONE of the synthetic gel substitutes have ever been correlated with living tissue. In our experience and that of the FBI BRF, NONE of the synthetic gel substitutes have proven as accurate as properly conducted, validated 10% gel studies.

—so I don't see the need to "re-invent the wheel".

If anyone wants to waste their time and money testing ammunition in the clear, synthetic gel, that's their prerogative.









*The manufacturer of the clear, synthetic gel routinely alters the formula of their product which is nothing more than a co-polymer plasticized by a paraffinic processing oil—which is Paralux 701 as last seen on a CBG purchase invoice that has circulated recently within industry channels.

[DocGKR]

The linked article in question appears to have so many flaws and accuracy errors as to render it irrelevant: https://www.policeone.com/police-products/firearms/accessories/ammunition/articles/ballistic-gelatin-comparisons-part-i-ndmFBGUHw79F9s0a. I wish the author had picked up the phone and called someone like Buford Boone, Scott Patterson, Mark Minisi, Sal Fanelli, or me and discussed the topic and history prior to writing....

[the Schwartz]

And it's not like you are hard to find. :)

[0ddl0t]

I would choose either of the designs based upon their performance in the 10% ordnance gelatin and/or in water. Both of these tissue analogs have long histories as valid terminal ballistic test mediums.

So you would completely ignore data that doesn't fit neatly into an academic paradigm?

I'm not just talking about clear gel. You'd also recognize no difference in terminal performance between this 147 gold dot from 3" barrel:
44801

and this 124 +P gold dot from a 3" barrel?
44802

(taken from: https://www.glocktalk.com/threads/g42-hollow-point-failure-test-8-layers-denim.1662442/ )

[the Schwartz]

So you would completely ignore data that doesn't fit neatly into an academic paradigm?

Yes—



I'm not just talking about clear gel. You'd also recognize no difference in terminal performance between this 147 gold dot from 3" barrel:
44801

and this 124 +P gold dot from a 3" barrel?
44802

(taken from: https://www.glocktalk.com/threads/g42-hollow-point-failure-test-8-layers-denim.1662442/ )

—especially if it involves relying upon shooting assorted grocery items (fruits, vegetables, deli-meats, etc.) to validate/legitimize testing conducted in the (still unproven) clear, synthetic gel.

[0ddl0t]

to validate/legitimize testing conducted in the (still unproven) clear, synthetic gel.

The motivation isn't to validate one particular medium, it is to ensure the ammunition is robust enough to function properly through a wide range of conditions.

If you are so wed to ordnance gel, I bet you could replicate the 147 gold dot's short barrel shortcomings by adding additional layers of clothing, or increasing the distance to the gel block, or chilling the ammo in a sub zero freezer before shooting.

Otherwise all you see is ~16" of penetration & ~0.56" final expansion and think it is comparable or even favorable to HST's 14" of penetration and .62" expansion without realizing you're just *barely* over the gold dot's expansion threshold.

[BehindBlueI's]

So you would completely ignore data that doesn't fit neatly into an academic paradigm?

We have a system that's proven to correlate to real world results. We have multiple alternatives that are not. I don't see why I would give them equal weight. Until one of the multiple "others" proves a correlation it's just noise clouding the signal.


I'm not just talking about clear gel. You'd also recognize no difference in terminal performance between this 147 gold dot from 3" barrel:
44801

and this 124 +P gold dot from a 3" barrel?
44802


I'd recognize terminal performance in assorted melons. I would not use that to draw any conclusions for terminal performance in people who are not made of melons.

[the Schwartz]

The motivation isn't to validate one particular medium, it is to ensure the ammunition is robust enough to function properly through a wide range of conditions.

If you are so wed to ordnance gel, I bet you could replicate the 147 gold dot's short barrel shortcomings by adding additional layers of clothing, or increasing the distance to the gel block, or chilling the ammo in a sub zero freezer before shooting.

Otherwise all you see is ~16" of penetration & ~0.56" final expansion and think it is comparable or even favorable to HST's 14" of penetration and .62" expansion without realizing you're just *barely* over the gold dot's expansion threshold.

Actually, I am "wed" to the scientific method which rules out introducing an entire host of unknown variables (esp. dubious, uncorrelated test mediums like fruits, vegetables, deli-meats, etc.) into terminal ballistic testing/evaluations. No need to "re-invent the wheel"--10% ordnance gelatin and water do all that is needed.

[0ddl0t]

Actually, I am "wed" to the scientific method which rules out introducing an entire host of unknown variables (esp. dubious, uncorrelated test mediums like fruits, vegetables, deli-meats, etc.) into terminal ballistic testing/evaluations. No need to "re-invent the wheel"--10% ordnance gelatin and water do all that is needed.

So you no longer ever encounter ammo that did not expand in the real world despite working well in gel or water?

Failures to expand in the real world is why the FBI added the heavy clothing test and continued failures to expand is why CHP/IWBA went further and switched to 4 layers of heavy denim. Obviously 4 layers of heavy denim is not realistic attire or a valid tissue simulant, but it helped improve testing and subsequent bullet designs. Still, by no means is it the end of the road.

While these tests work pretty well for duty-sized guns, problems continue to exist at the boundaries (both from carbine length barrels and from micro pistol-sized barrels). The examination of these anomalies - using the scientific method - has value.

[BehindBlueI's]

While these tests work pretty well for duty-sized guns, problems continue to exist at the boundaries (both from carbine length barrels and from micro pistol-sized barrels). The examination of these anomalies - using the scientific method - has value.

A bullet out of it's designed speed envelope isn't going to work as designed. The answer isn't that somehow short barrels need different testing methods. The answer is to test the bullets in the same fps range that they leave the shorter/longer barrel from in the same protocols that "normal" barrel lengths are tested at, which is done.

[the Schwartz]

So you no longer ever encounter ammo that did not expand in the real world despite working well in gel or water?

When did I ever say that? (Note: I didn't and haven't; not here in this topic thread or anywhere else)

Prior to this point in this thread, we've been discussing the validity/relevance of test mediums. I've confined my commentary specifically to that topic, so I am not sure how it is that you've suddenly come to the conclusion that I am now disputing the validity/relevance of placing intermediate material barriers (such as those used in the FBI test protocols) in front of any valid terminal ballistic test medium (10% gel or H2O) for the purpose of evaluating their effects.


Failures to expand in the real world is why the FBI added the heavy clothing test and continued failures to expand is why CHP/IWBA went further and switched to 4 layers of heavy denim. Obviously 4 layers of heavy denim is not realistic attire or a valid tissue simulant, but it helped improve testing and subsequent bullet designs. Still, by no means is it the end of the road.

While these tests work pretty well for duty-sized guns, problems continue to exist at the boundaries (both from carbine length barrels and from micro pistol-sized barrels). The examination of these anomalies - using the scientific method - has value.

I get the sense that you are attempting to make a point, but "moving the goal posts" in terms of the subject (test mediums ===> barriers) being discussed makes whatever point you are attempting difficult to discern.

[0ddl0t]

A bullet out of it's designed speed envelope isn't going to work as designed. The answer isn't that somehow short barrels need different testing methods. The answer is to test the bullets in the same fps range that they leave the shorter/longer barrel from in the same protocols that "normal" barrel lengths are tested at, which is done.
If the test was all encompassing & perfect, sure. In reality it is not.

Because almost all defensive ammo is designed to perform robustly from duty pistols, and almost all the professional testing involves duty ammo from duty pistols, the flaws in the existing gel tests aren't as apparent because none of the ammo is squeaking by at the edges of their performance envelopes.

Start playing around at the boundaries and you realize the existing tests might not offer as much cushion & clarity as you'd like.


I get the sense that you are attempting to make a point, but "moving the goal posts" in terms of the subject (test mediums ===> barriers) being discussed makes whatever point you are attempting difficult to discern.
My point is that the existing tests of 10% gel & 10% gel behind 4 layers of denim are imperfect for many of the popular concealed carry guns on the market. Repeatable tests in other media or with alternate intermediate barriers can illustrate real deficiencies left uncovered by these traditional tests.

As an example, I give the gold dot 147 from a 3" barrel which is on Doc's list of recommended ammo and which reliably expands in traditional testing with 10% ordnance gel. But if you lower ρ (using lower density media) or V (by adding distance, barriers, etc) even slightly it begins to fail to expand.

That gold dot 147s are at the lower bounds of their performance window from a 3" barrel is useful information to know & that information can be reliably and repeatedly discerned from non traditional (but scientifically valid) tests.

[BehindBlueI's]

If the test was all encompassing & perfect, sure. In reality it is not.

Because almost all defensive ammo is designed to perform robustly from duty pistols, and almost all the professional testing involves duty ammo from duty pistols, the flaws in the existing gel tests aren't as apparent because none of the ammo is squeaking by at the edges of their performance envelopes.

Start playing around at the boundaries and you realize the existing tests might not offer as much cushion & clarity as you'd like.



Even if we accept that as fact, the answer is to repeat the protocol that's proven to correlate to the real world but at the fps you find from the shorter/longer barrel. The answer is not to shoot melons or pudding filled pinatas or whatever.

[KellyinAvon]

Even if we accept that as fact, the answer is to repeat the protocol that's proven to correlate to the real world but at the fps you find from the shorter/longer barrel. The answer is not to shoot melons or pudding filled pinatas or whatever.

Suddenly I'm getting the urge to fill a pinata with pudding, and shoot it. I thinking shoot it with a deer slug. I don't remember reading anything at my local range that this is specifically forbidden.

[the Schwartz]

My point is that the existing tests of 10% gel & 10% gel behind 4 layers of denim are imperfect for many of the popular concealed carry guns on the market. Repeatable tests in other media or with alternate intermediate barriers can illustrate real deficiencies left uncovered by these traditional tests.

As an example, I give the gold dot 147 from a 3" barrel which is on Doc's list of recommended ammo and which reliably expands in traditional testing with 10% ordnance gel. But if you lower ρ (using lower density media) or V (by adding distance, barriers, etc) even slightly it begins to fail to expand.

That gold dot 147s are at the lower bounds of their performance window from a 3" barrel is useful information to know & that information can be reliably and repeatedly discerned from non traditional (but scientifically valid) tests.

What, specifically, are the materials (that is, what test medium?) used in these "non-traditional (but scientifically valid) tests"?

[the Schwartz]

Suddenly I'm getting the urge to fill a pinata with pudding, and shoot it. I thinking shoot it with a deer slug. I don't remember reading anything at my local range that this is specifically forbidden.

If you do this, please post video. And make it vanilla pudding. I hate vanilla pudding so it's got it comin'. :cool:

[DocGKR]

Note that virtually every decent ballistic test facility that conducts valid research has frequently experimented with a variety of simulants to determine if something has been developed which is superior to the current 10% ordnance gel or has a better correlation with living tissue.....so far nothing better has been discovered.

[0ddl0t]

Even if we accept that as fact, the answer is to repeat the protocol that's proven to correlate to the real world but at the fps you find from the shorter/longer barrel. The answer is not to shoot melons or pudding filled pinatas or whatever.
Doing the same thing over and over and expecting different results is insanity.

And that whole "proven correlation" is mildly overstated. Best I can tell it comes from a study of 28 Winchester bullets recovered at autopsy in San Diego from 1987-1991. But the study excluded any bullet that left the body or hit bone which means the sample pretty much self-selected only the bullets that expanded properly.

I don't have the exact numbers to run a correlation check because the author just gave a summary of the gel test: 20 shots varying from 12-14" penetration with a ratio of 1.20 But he did list all the individual bullets from autopsy, which varied from 10-17" in penetration and ratios of 0.85-1.43.

To quote the author (Gene Wolberg):

"Shots fired into correctly prepared gelatin tissue simulant can be a valuable guideline in the selection of police ammunition. It is most useful in separating out the grossly inadequate bullets: those that penetrate only 6 or 7 inches or SP/HP that do not expand adequately."

For a rough correlation comparison, here is BrassFetcher's data comparing penetration in clear and organic gel:

cal....OG...CB
.380 7.6 9.6
9mm 13.7 13.4
357s 15.0 13.2
12gs 11.9 13.3
12g#4 11.6 11.0

Pearson Correlation Coefficient: 0.8742 (moderate-high correlation)


What, specifically, are the materials (that is, what test medium?) used in these "non-traditional (but scientifically valid) tests"?
Anything you can repeatedly use with enough consistency to be valid. You could use water mixed to a specific ratio with a less dense fluid like rubbing alcohol (or add something like salt to increase density). You could use clear gel if you can ensure consistency from one block to the next. You could use butter or margarine or mozzarella or whatever gelatinous substance you can find that is consistent from one batch to the next and has the properties you're interested in exploring.

Again the point isn't to replace ordnance gel, but to supplement it with additional data from different media.

Or you could still use ordnance gel, but stick your ammo in a sub zero freezer overnight to drop velocity ~30fps. Or heat them to 150° to add ~30fps. Or add a 5th or 6th layer of denim. Or add a 1" barrier of fat/grease barrier to ordnance gel.

As a short barrel guy, I'd be interested in lower density media and/or lower velocity testing, but a carbine guy might want to go the other way.

[Half Moon]

Suddenly I'm getting the urge to fill a pinata with pudding, and shoot it. I thinking shoot it with a deer slug. I don't remember reading anything at my local range that this is specifically forbidden.

I'm strongly feeling, for that test to be valid, Doug Mercaido from Forged In Fire needs involved:

`Your bullet, sir, will... kill`

[BehindBlueI's]

Doing the same thing over and over and expecting different results is insanity.


So your claim is that 10% gel is only good within certain fps ranges? That the results are invalid outside of those ranges? What are those ranges and how did you arrive at them?

What medium has proven correlation in those "invalid" ranges?

How did you determine that?


And that whole "proven correlation" is mildly overstated. Best I can tell it comes from a study of 28 Winchester bullets recovered at autopsy in San Diego from 1987-1991. But the study excluded any bullet that left the body or hit bone which means the sample pretty much self-selected only the bullets that expanded properly.

No, it isn't. The current FBI protocols have a proven correlation with real world OIS, with a hell of a lot bigger and more recent sample then 28 bullets from 30 years ago from the time the protocol was originally being developed.


20 shots varying from 12-14" penetration with a ratio of 1.20 But he did list all the individual bullets from autopsy, which varied from 10-17" in penetration and ratios of 0.85-1.43.

Do you think penetration is the exact same in all of the tests of the FBI protocols? That a bullet penetrates the same after going through auto glass as it does bare gel or 4LD? No. That's why there is more than one stage in the protocols. Why would you expect the same penetration in a human body every time?

[the Schwartz]

Anything you can repeatedly use with enough consistency to be valid. You could use water mixed to a specific ratio with a less dense fluid like rubbing alcohol (or add something like salt to increase density). You could use clear gel if you can ensure consistency from one block to the next. You could use butter or margarine or mozzarella or whatever gelatinous substance you can find that is consistent from one batch to the next and has the properties you're interested in exploring.

Again the point isn't to replace ordnance gel, but to supplement it with additional data from different media.

Or you could still use ordnance gel, but stick your ammo in a sub zero freezer overnight to drop velocity ~30fps. Or heat them to 150° to add ~30fps. Or add a 5th or 6th layer of denim. Or add a 1" barrier of fat/grease barrier to ordnance gel.

As a short barrel guy, I'd be interested in lower density media and/or lower velocity testing, but a carbine guy might want to go the other way.

Modeling terminal ballistic performance in human tissue is not as simple as firing bullets into a substance of a desired density and then concluding that the terminal behavior seen in that material corresponds with what occurs in a human body. Valid physical models, like 10% ordnance gelatin and water, have been shown through extensive research to correlate strongly with living tissue in terms of their material properties. Since the desired objective is to accurately represent a projectile's terminal performance in human tissue, only those specific mediums that can be shown to demonstrate the correct physical properties are valid as a means of modeling such performance. Beyond considering only the mass density of a solid test medium, a solid must also demonstrate the correct shear response within the typical magnitude of strain rates observed in such testing. Data obtained from "different media" that you've suggested above such as butter, margarine, mozzarella cheese, and for that matter, fruits, vegetables, and deli-meats, are not "supplemental" at all; in fact, they are specious and lack evidence that supports their validity as a terminal ballistic test medium that correlates with human tissue.

The clear, synthetic gel product, with its frequent changes in composition and component sourcing, is also unsuitable not only for the undocumented changes in its formulation but also for the failure of the manufacturer(s) of these products to provide information on how these changes in composition and source compare against previous iterations of their product(s).

Modeling terminal ballistic performance in fluids/liquids requires more than matching density (ρ) to achieve dynamic equivalence with soft tissue. In order to properly represent terminal performance in soft tissue, the candidate fluid/liquid must also possess the same bulk modulus (K) and internal sonic velocity (c) which are all related to one another in the Newton-LaPlace formula— c = √(K/ρ)

The internal speed of sound in isopropyl "rubbing" alcohol, C3H8O, is c = 1,205 ms-1, its density is ρ = 786 kg/m³ so by extension of the Newton-LaPlace formula, its bulk modulus is K = 1.141 GPa.

Compared to the respective values of c, ρ, and K in water, 10% ordnance gelatin, and human soft tissue—

H2O: c = 1,497 ms-1, ρ = 999.87 kg/m³, K = 2.24 GPa
10% ordnance gelatin: c = 1,494 ms-1, ρ = 1,040.00 kg/m³, K = 2.32 GPa
Typical values for human soft tissue: c = 1,540 ms-1, ρ = 1,020 kg/m³, K = 2.42 GPa

—isopropyl alcohol does not compare favorably with any of these materials' values and therefore is not an acceptable candidate fluid (mixed with water or by itself) for modeling terminal ballistic response as it occurs in human tissue. No such research suggesting otherwise exists.

Due to the frequent and unknown changes in its formulation, it is also difficult to ascertain values of c, ρ, and K of the clear, synthetic gel. The only physical property of the clear, synthetic gel that is known has been subject to some variance at different times within the same source ranging from 790 kg/m³ - 824 kg/m³ with no known values for either its internal sonic velocity or bulk modulus.

Given the lack of supporting research that "ensures the consistency" of any of the "different media" that you've suggested, their use is likely to yield dubious data at best. At worst, relying on that data leads to inaccurate, and possibly dangerous, conclusions being drawn about the ammunition tested in those uncorrelated mediums.

[0ddl0t]

So your claim is that 10% gel is only good within certain fps ranges?
No. My claim is that a bullet at the low end of the range of fps that expands in ordnance gel may well not expand in human tissue at that same fps.


How did you determine that?
A single local autopsy where the decedent was shot twice with gold dot 147s from a 3.1" shield at nearly point blank range. 1 went through and the other entered between ribs, went laterally through his chest hitting lung & heart, and was stopped by a rib. Shot placement did the job, but the bullet failed to expand despite having a good track record with a local department in duty weapons.

Subsequent research shows this particular combo of gun & ammo often fails to expand in clear gel, meat targets, melons, etc yet performs well in ordnance gel.



No, it isn't. The current FBI protocols have a proven correlation with real world OIS, with a hell of a lot bigger and more recent sample then 28 bullets from 30 years ago from the time the protocol was originally being developed.
Dogmatic reliance on *just* the FBI tests can leave you susceptible to adopting faulty ammo you later need to recall - like the G2 (the highest scoring round in FBI history)


Modeling terminal ballistic performance in human tissue is not as simple as firing bullets into a substance of a desired density and then concluding that the terminal behavior seen in that material corresponds with what occurs in a human body.
Exactly. Given the inconsistent composition of human bodies we should be looking at behaviors in multiple simulants.



Valid physical models, like 10% ordnance gelatin and water, have been shown through extensive research to correlate strongly with living tissue in terms of their material properties.
10% OG has been shown to correlate with the average properties of living tissues.



Modeling terminal ballistic performance in fluids/liquids requires more than matching density (ρ) to achieve dynamic equivalence with soft tissue. In order to properly represent terminal performance in soft tissue, the candidate fluid/liquid must also possess the same bulk modulus (K) and internal sonic velocity (c) which are all related to one another in the Newton-LaPlace formula— c = √(K/ρ)

The internal speed of sound in isopropyl "rubbing" alcohol, C3H8O, is c = 1,205 ms-1, its density is ρ = 786 kg/m³ so by extension of the Newton-LaPlace formula, its bulk modulus is K = 1.141 GPa.

Compared to the respective values of c, ρ, and K in water, 10% ordnance gelatin, and human soft tissue—

H2O: c = 1,497 ms-1, ρ = 999.87 kg/m³, K = 2.24 GPa
10% ordnance gelatin: c = 1,494 ms-1, ρ = 1,040.00 kg/m³, K = 2.32 GPa
Typical values for human soft tissue: c = 1,540 ms-1, ρ = 1,020 kg/m³, K = 2.42 GPa

—isopropyl alcohol does not compare favorably with any of these materials' values and therefore is not an acceptable candidate fluid (mixed with water or by itself) for modeling terminal ballistic response as it occurs in human tissue. No such research suggesting otherwise exists.

Within reason (e.g. shooting water not ice), the properties that affect expansion are density & velocity. For this supplemental test I'm not interested in correlating penetration depth, just checking for a robust margin of expansion.



Given the lack of supporting research that "ensures the consistency" of any of the "different media" that you've suggested, their use is likely to yield dubious data at best. At worst, relying on that data leads to inaccurate, and possibly dangerous, conclusions being drawn about the ammunition tested in those uncorrelated mediums.
What danger exists in selecting ammunition that passes both the traditional FBI/IWBA tests and still shows valid expansion in alternative media?

[BehindBlueI's]

A single local autopsy where the decedent was shot twice with gold dot 147s from a 3.1" shield at nearly point blank range.

How did the Gold dot do in the entirety of the FBI protocol at the fps it was launched from the Shield?



Dogmatic reliance on *just* the FBI tests can leave you susceptible to adopting faulty ammo you later need to recall - like the G2 (the highest scoring round in FBI history)

Was that a problem with the test or a problem with unannounced changes/manufacturing errors with the ammunition?

[Duelist]

Modeling terminal ballistic performance in human tissue is not as simple as firing bullets into a substance of a desired density and then concluding that the terminal behavior seen in that material corresponds with what occurs in a human body. Valid physical models, like 10% ordnance gelatin and water, have been shown through extensive research to correlate strongly with living tissue in terms of their material properties. Since the desired objective is to accurately represent a projectile's terminal performance in human tissue, only those specific mediums that can be shown to demonstrate the correct physical properties are valid as a means of modeling such performance. Beyond considering only the mass density of a solid test medium, a solid must also demonstrate the correct shear response within the typical magnitude of strain rates observed in such testing. Data obtained from "different media" that you've suggested above such as butter, margarine, mozzarella cheese, and for that matter, fruits, vegetables, and deli-meats, are not "supplemental" at all; in fact, they are specious and lack evidence that supports their validity as a terminal ballistic test medium that correlates with human tissue.

The clear, synthetic gel product, with its frequent changes in composition and component sourcing, is also unsuitable not only for the undocumented changes in its formulation but also for the failure of the manufacturer(s) of these products to provide information on how these changes in composition and source compare against previous iterations of their product(s).

Modeling terminal ballistic performance in fluids/liquids requires more than matching density (ρ) to achieve dynamic equivalence with soft tissue. In order to properly represent terminal performance in soft tissue, the candidate fluid/liquid must also possess the same bulk modulus (K) and internal sonic velocity (c) which are all related to one another in the Newton-LaPlace formula— c = √(K/ρ)

The internal speed of sound in isopropyl "rubbing" alcohol, C3H8O, is c = 1,205 ms-1, its density is ρ = 786 kg/m³ so by extension of the Newton-LaPlace formula, its bulk modulus is K = 1.141 GPa.

Compared to the respective values of c, ρ, and K in water, 10% ordnance gelatin, and human soft tissue—

H2O: c = 1,497 ms-1, ρ = 999.87 kg/m³, K = 2.24 GPa
10% ordnance gelatin: c = 1,494 ms-1, ρ = 1,040.00 kg/m³, K = 2.32 GPa
Typical values for human soft tissue: c = 1,540 ms-1, ρ = 1,020 kg/m³, K = 2.42 GPa

—isopropyl alcohol does not compare favorably with any of these materials' values and therefore is not an acceptable candidate fluid (mixed with water or by itself) for modeling terminal ballistic response as it occurs in human tissue. No such research suggesting otherwise exists.

Due to the frequent and unknown changes in its formulation, it is also difficult to ascertain values of c, ρ, and K of the clear, synthetic gel. The only physical property of the clear, synthetic gel that is known has been subject to some variance at different times within the same source ranging from 790 kg/m³ - 824 kg/m³ with no known values for either its internal sonic velocity or bulk modulus.

Given the lack of supporting research that "ensures the consistency" of any of the "different media" that you've suggested, their use is likely to yield dubious data at best. At worst, relying on that data leads to inaccurate, and possibly dangerous, conclusions being drawn about the ammunition tested in those uncorrelated mediums.

Science!

[0ddl0t]

How did the Gold dot do in the entirety of the FBI protocol at the fps it was launched from the Shield?
The Gold dot 147 (original, not g2) performs well in bare gel & through iwba 4ld from a 3.0" PM9.



Was that a problem with the test or a problem with unannounced changes/manufacturing errors with the ammunition?
Speer was tight lipped, but the G2 V2's skive and seating depth differences are more than a single manufacturing error.

Recalled G2:
44839

Version 2 G2:
44840

[the Schwartz]

Exactly. Given the inconsistent composition of human bodies we should be looking at behaviors in multiple simulants.

I don't know how else to say it, make it any clearer, or explain it any more clearly than I have. The fact that you have elected to ignore the underlying science that defines the physical material properties necessary for a substance to qualify as a valid terminal ballistic test medium suggests that you have either simply rejected it out of hand or don't understand its relevance or both. I've provided sourced, confirmable information describing the physical material properties of the two valid test mediums presently being used by labs across the nation. The information presented in my prior posts is open to analysis and review in support of the principle of dynamic equivalence being necessary in a test medium if it is to represent terminal ballistic performance of projectiles in human soft tissue. Unless you can substantiate the same physical material properties for any of the "different mediums" suggested in your prior posts—those being butter, margarine, mozzarella cheese, fruits, vegetables, and deli-meats—so that they can be compared directly to the respective values of c, ρ, and K for water, 10% ordnance gelatin, and human soft tissue, any suggestion that butter, margarine, mozzarella cheese, fruits, vegetables, and deli-meats are valid test mediums fails to stand on its own especially when they are subjected to examination under the same standard as the other human tissue simulants.

In other words, if you shoot a block of butter with a bullet that expands in it, it doesn't mean anything other than that the bullet expanded when it was fired into butter and in no way suggests that the same result can be expected of it if it is fired into human soft tissue. If you shoot a block of margarine with a bullet that expands in it, it doesn't mean anything other than that the bullet expanded when it was fired into margarine and in no way suggests that the same result can be expected of it if it is fired into human soft tissue. If you shoot a block of mozzarella cheese with a bullet that expands in it, it doesn't mean anything other than that the bullet expanded when it was fired into mozzarella cheese and in no way suggests that the same result can be expected of it if it is fired into human soft tissue.

Terminal ballistic testing in properly prepared 10% ordnance gelatin and water closely represents the response of the bullet that strikes human soft tissue.

44845

None of the "different mediums" (butter, margarine, mozzarella cheese, fruits, vegetables, deli-meats) suggested in your prior posts can make that claim and are representative of nothing other than terminal ballistic performance in themselves. Ignoring these facts and underlying science does not validate these "different mediums".

[the Schwartz]

Modeling terminal ballistic performance in human tissue is not as simple as firing bullets into a substance of a desired density and then concluding that the terminal behavior seen in that material corresponds with what occurs in a human body. Valid physical models, like 10% ordnance gelatin and water, have been shown through extensive research to correlate strongly with living tissue in terms of their material properties. Since the desired objective is to accurately represent a projectile's terminal performance in human tissue, only those specific mediums that can be shown to demonstrate the correct physical properties are valid as a means of modeling such performance. Beyond considering only the mass density of a solid test medium, a solid must also demonstrate the correct shear response within the typical magnitude of strain rates observed in such testing. Data obtained from "different media" that you've suggested above such as butter, margarine, mozzarella cheese, and for that matter, fruits, vegetables, and deli-meats, are not "supplemental" at all; in fact, they are specious and lack evidence that supports their validity as a terminal ballistic test medium that correlates with human tissue.

The clear, synthetic gel product, with its frequent changes in composition and component sourcing, is also unsuitable not only for the undocumented changes in its formulation but also for the failure of the manufacturer(s) of these products to provide information on how these changes in composition and source compare against previous iterations of their product(s).

Modeling terminal ballistic performance in fluids/liquids requires more than matching density (ρ) to achieve dynamic equivalence with soft tissue. In order to properly represent terminal performance in soft tissue, the candidate fluid/liquid must also possess the same bulk modulus (K) and internal sonic velocity (c) which are all related to one another in the Newton-LaPlace formula— c = √(K/ρ)

The internal speed of sound in isopropyl "rubbing" alcohol, C3H8O, is c = 1,205 ms-1, its density is ρ = 786 kg/m³ so by extension of the Newton-LaPlace formula, its bulk modulus is K = 1.141 GPa.

Compared to the respective values of c, ρ, and K in water, 10% ordnance gelatin, and human soft tissue—

H2O: c = 1,497 ms-1, ρ = 999.87 kg/m³, K = 2.24 GPa
10% ordnance gelatin: c = 1,494 ms-1, ρ = 1,040.00 kg/m³, K = 2.32 GPa
Typical values for human soft tissue: c = 1,540 ms-1, ρ = 1,020 kg/m³, K = 2.42 GPa

—isopropyl alcohol does not compare favorably with any of these materials' values and therefore is not an acceptable candidate fluid (mixed with water or by itself) for modeling terminal ballistic response as it occurs in human tissue. No such research suggesting otherwise exists.

Due to the frequent and unknown changes in its formulation, it is also difficult to ascertain values of c, ρ, and K of the clear, synthetic gel. The only physical property of the clear, synthetic gel that is known has been subject to some variance at different times within the same source ranging from 790 kg/m³ - 824 kg/m³ with no known values for either its internal sonic velocity or bulk modulus.

Given the lack of supporting research that "ensures the consistency" of any of the "different media" that you've suggested, their use is likely to yield dubious data at best. At worst, relying on that data leads to inaccurate, and possibly dangerous, conclusions being drawn about the ammunition tested in those uncorrelated mediums.


Science!

Exactly!

I am pleased and encouraged to see that there are P-F members here who have not discarded the scientific method in favor of baseless, unsupported opinion. :cool:

[BehindBlueI's]

The Gold dot 147 (original, not g2) performs well in bare gel & through iwba 4ld from a 3.0" PM9.

Which does not answer my question. There is a reason the FBI protocol is more than bare gel and 4LD.

I'll repeat, how did the Gold dot do in the entirety of the FBI protocol at the fps it was launched from the Shield?



Speer was tight lipped, but the G2 V2's skive and seating depth differences are more than a single manufacturing error.


So if a given bullet passes and then the bullet changes and doesn't fare well...what's that got to do with the validity of the test of the original bullet? Hint: Nothing.

[KellyinAvon]

If you do this, please post video. And make it vanilla pudding. I hate vanilla pudding so it's got it comin'. :cool:

I'm thinking they won't let me back on the range if I did that. It's two miles from the house, really convenient. I'm picturing a video played completely straight, "Please note I'm filling the authentic pinata with vanilla pudding. NOT INSTANT, this is real vanilla pudding I'm using as my ballistic material. My authentic pinata is from Wal-Mart and was made in China. My Winchester Model 1200 has a 26 inch barrel, is full choke, and kicks like a mule. The Hornady slugs are totally badass."

[0ddl0t]

We're starting to go round and round - I'll make these points one last time...


I don't know how else to say it, make it any clearer, or explain it any more clearly than I have. The fact that you have elected to ignore the underlying science that defines the physical material properties necessary for a substance to qualify as a valid terminal ballistic test medium suggests that you have either simply rejected it out of hand or don't understand its relevance or both.
I haven't, yet you continue to make this straw man case. I tried bolding the question last time in hopes you would address it, but let me try adding a larger font this time too:

What danger exists in selecting ammunition that passes both the traditional FBI/IWBA tests and still shows valid expansion in alternative media?

It seems to me the only danger is in acknowledging that the existing tests, which have more or less remained unchanged for 25 years, might not be so perfect (something that was readily acknowledged 25 years ago - and something that should be blatantly obvious now that the "highest scoring FBI round" is no longer being used by the FBI).



Terminal ballistic testing in properly prepared 10% ordnance gelatin and water correctly represents the response of the bullet that strikes human soft tissue.
If that were true we wouldn't have the heavy clothing and 4 layers of denim tests because water & 10% OG both overstate expansion seen in real life. Heavy clothing and denim obviously do not have comparable speeds of sound or bulk moduli to living tissue (nor do they represent reasonable clothing). Are you telling me their additions to FBI/IWBA protocols were not scientifically valid?



Which does not answer my question. There is a reason the FBI protocol is more than bare gel and 4LD.

I'll repeat, how did the Gold dot do in the entirety of the FBI protocol at the fps it was launched from the Shield?
I have not tested it, nor am I aware of anyone who has. I personally don't test through barriers I'm unlikely to encounter as a civilian.


So if a given bullet passes and then the bullet changes and doesn't fare well...what's that got to do with the validity of the test of the original bullet? Hint: Nothing.
Do you have evidence there was a change after the FBI tested it, but before it reached consumers? The recalled G2 still performed well from Glock 17s in 10% ordinance gel...

[the Schwartz]

Are you telling me their additions to FBI/IWBA protocols were not scientifically valid?

Nothing that I have said so far on this forum could ever—not even remotely—be construed in that way.





We're starting to go round and round - I'll make these points one last time...

I haven't, yet you continue to make this straw man case. I tried bolding the question last time in hopes you would address it, but let me try adding a larger font this time too:

What danger exists in selecting ammunition that passes both the traditional FBI/IWBA tests and still shows valid expansion in alternative media?

It seems to me the only danger is in acknowledging that the existing tests, which have more or less remained unchanged for 25 years, might not be so perfect (something that was readily acknowledged 25 years ago - and something that should be blatantly obvious now that the "highest scoring FBI round" is no longer being used by the FBI).

If that were true we wouldn't have the heavy clothing and 4 layers of denim tests because water & 10% OG both overstate expansion seen in real life. Heavy clothing and denim obviously do not have comparable speeds of sound or bulk moduli to living tissue (nor do they represent reasonable clothing). Are you telling me their additions to FBI/IWBA protocols were not scientifically valid?

I think that it might be wise for you to cool-off for a bit.

[the Schwartz]

I'm thinking they won't let me back on the range if I did that. It's two miles from the house, really convenient. I'm picturing a video played completely straight, "Please note I'm filling the authentic pinata with vanilla pudding. NOT INSTANT, this is real vanilla pudding I'm using as my ballistic material. My authentic pinata is from Wal-Mart and was made in China. My Winchester Model 1200 has a 26 inch barrel, is full choke, and kicks like a mule. The Hornady slugs are totally badass."

As you are probably aware, I was kidding. Not about hating vanilla pudding (I really do), but shooting something like that on your range. I'd hate to see anyone kicked off of their shooting spot for something like that. :)

[BehindBlueI's]

I have not tested it, nor am I aware of anyone who has. I personally don't test through barriers I'm unlikely to encounter as a civilian.

So the backbone of your claim is based on an autopsy not matching the test results of which you don't actually know what the results were? Do you see that as potentially problematic to your claim? Unless one assumes all of the other tests besides bare and 4LD are superfluous and done just for funsies? Passing the entirety of the protocols = real world correlation. Auto glass testing results are pretty similar to bone strike results, that sort of thing.



Do you have evidence there was a change after the FBI tested it, but before it reached consumers?

Other than the common knowledge that crates of contract reject ammo that was sold to the civilian market, pictures showing obvious differences between individual bullets, and insider chatter about serious QC issues? No, nothing personally.




The recalled G2 still performed well from Glock 17s in 10% ordinance gel...

We're back where we started. That tells you how it performs at that fps range. It doesn't tell you how it performs at faster or slower fps ranges. The answer to finding that out is the proper testing procedures done at the fps range in question, not shooting a pinanta filled with pudding.

[JAD]

What danger exists in selecting ammunition that passes both the traditional FBI/IWBA tests and still shows valid expansion in alternative media?[/B]
...

Generally if you mix bad data with good data the admixture is bad. Tests on uncontrolled media produce bad data.

[KellyinAvon]

As you are probably aware, I was kidding. Not about hating vanilla pudding (I really do), but shooting something like that on your range. I'd hate to see anyone kicked off of their shooting spot for something like that. :)

Oh I would never do this on a range. Out in the country? That's a whole other matter. I'm so wanting to do this, the hard part would be not laughing in the video.

[the Schwartz]

Oh I would never do this on a range. Out in the country? That's a whole other matter. I'm so wanting to do this, the hard part would be not laughing in the video.

Giggling maniacally before, during, and after shooting your pudding-filled pinata would only enhance the value of such a video.

[0ddl0t]

So the backbone of your claim is based on an autopsy not matching the test results of which you don't actually know what the results were? Do you see that as potentially problematic to your claim? Unless one assumes all of the other tests besides bare and 4LD are superfluous and done just for funsies? Passing the entirety of the protocols = real world correlation. Auto glass testing results are pretty similar to bone strike results, that sort of thing.
The bullet in question struck no bone until it came to a rest - barriers did not affect its lack of expansion.



Other than the common knowledge that crates of contract reject ammo that was sold to the civilian market, pictures showing obvious differences between individual bullets, and insider chatter about serious QC issues? No, nothing personally.
Have a link to this "common knowledge" of crates of G2 reject ammo being sold to civilians? Seems like the sort of thing that could end consumer confidence in a brand...

I'm aware of Federal selling lower grades of green tip ammo, but those packages had identifiers on the SKU.



We're back where we started. That tells you how it performs at that fps range. It doesn't tell you how it performs at faster or slower fps ranges. The answer to finding that out is the proper testing procedures done at the fps range in question, not shooting a pinanta filled with pudding.
And at that same fps it failed to perform in clear gel. Hobbyists using clear gel are what exposed the issue to the public...


Generally if you mix bad data with good data the admixture is bad. Tests on uncontrolled media produce bad data.
That's true if mixing data. Here the data is siloed. If a bullet passes traditional fbi/iwba tests, then it is supposedly good to go, right? So what difference is it to John Moses Browning if I subselect only those with blue primer sealant or only those that expand when shot through a cantaloupe?

[Caballoflaco]

Have a link to this "common knowledge" of crates of G2 reject ammo being sold to civilians? Seems like the sort of thing that could end consumer confidence in a brand...

?

Check the g2 gold dot thread here:

https://pistol-forum.com/showthread.php?13776-Speer-Gold-Dot-G2-147-grain-PT-9mm&p=954900&viewfull=1#post954900

[KellyinAvon]

Giggling maniacally before, during, and after shooting your pudding-filled pinata would only enhance the value of such a video.

You mean like, "BU-WA-HAHAHAHAHHAHAHAHAHAHA!!!!"

I don't know about posting videos, I'll have to ask my children about it.

[BehindBlueI's]

Have a link to this "common knowledge" of crates of G2 reject ammo being sold to civilians? Seems like the sort of thing that could end consumer confidence in a brand...


There's at least two threads on this very forum dealing with the matter. One's already been linked for you by another helpful poster.


So what difference is it to John Moses Browning if I subselect only those with blue primer sealant or only those that expand when shot through a cantaloupe?

For you? Nothing. I often argue these points not to change the poster's mind. I realize it's tilting at a windmill as the real goal is validation, not learning or a critical examination of the belief. You've been presented with what I would consider compelling counter-arguments while failing to mount an effective defense for your position. I do so for those who might be a blank slate, wander in, and find your fruit salad based testing compelling if it's not countered with facts. If they then also decide fruit salad testing is the way to go, at least they had the opportunity to hear the counterpoint. Carry RIP ammo if you like, absolutely nothing to me until you try and convince others how great it is.

[0ddl0t]

There's at least two threads on this very forum dealing with the matter. One's already been linked for you by another helpful poster.

I must have misunderstood. I am aware Speer sold reject ammo very clearly marked "training ammo only" "not for duty use." I am not aware of Speer selling QC reject ammo in normal defensive/LE packaging to unwitting consumers (i.e. the initial run of G2 that wound up recalled).



I do so for those who might be a blank slate, wander in, and find your fruit salad based testing compelling if it's not countered with facts.
And that is why I post here, so folks might be aware of the downsides taking only the word of unquestioned experts, rather than doing any validation testing of their own:


"The Speer 9 mm 147 gr G2 is very good performing barrier blind ammunition! In fact modern 9 mm ammo like the G2 performs so well, that many large LE agencies are having no issues giving up larger caliber handguns in favor of easier shooting, more durable, higher capacity 9 mm handguns that offer terminal performance that only a few years ago was only possible with larger calibers like .40 S&W and .45 Auto."
Dr. Gary Roberts 2014

[Duelist]

I must have misunderstood. I am aware Speer sold reject ammo very clearly marked "training ammo only" "not for duty use." I am not aware of Speer selling QC reject ammo in normal defensive/LE packaging to unwitting consumers (i.e. the initial run of G2 that wound up recalled).


And that is why I post here, so folks might be aware of the downsides taking only the word of unquestioned experts, rather than doing any validation testing of their own:


"The Speer 9 mm 147 gr G2 is very good performing barrier blind ammunition! In fact modern 9 mm ammo like the G2 performs so well, that many large LE agencies are having no issues giving up larger caliber handguns in favor of easier shooting, more durable, higher capacity 9 mm handguns that offer terminal performance that only a few years ago was only possible with larger calibers like .40 S&W and .45 Auto."
Dr. Gary Roberts 2014


So, your “problem” is with Dr. Roberts?

[0ddl0t]

So, your “problem” is with Dr. Roberts?

No. Both he & Charles Schwartz are wealths of information who know more about wound ballistics than I likely every will and they have been very generous in freely sharing their knowledge with us. I just suspect both are more concerned about defending consumers from charlatans than acknowledging, investigating, & correcting the flaws remaining in traditional testing.

As proof of those lingering flaws I gave the example of 1 bullet design, out of the hundreds Dr. Roberts has reviewed, that performed exceptionally well in his tests but failed so miserably in the real world it was recalled & tweaked before rerelease.

[scjbash]

Fifty posts of math and pudding and it still boils down to this.


The keys are:

-- Cultivate a warrior mindset
-- Invest in competent, thorough initial training and then maintain skills with regular ongoing practice
-- Acquire a reliable and durable weapon system
-- Purchase a consistent, robust performing duty/self-defense load in sufficient quantities (at least 1000 rounds) then STOP worrying about the nuances of handgun ammunition terminal performance.


Shot placement did the job

[Spartan1980]

Modeling terminal ballistic performance in human tissue is not as simple as firing bullets into a substance of a desired density and then concluding that the terminal behavior seen in that material corresponds with what occurs in a human body. Valid physical models, like 10% ordnance gelatin and water, have been shown through extensive research to correlate strongly with living tissue in terms of their material properties. Since the desired objective is to accurately represent a projectile's terminal performance in human tissue, only those specific mediums that can be shown to demonstrate the correct physical properties are valid as a means of modeling such performance. Beyond considering only the mass density of a solid test medium, a solid must also demonstrate the correct shear response within the typical magnitude of strain rates observed in such testing. Data obtained from "different media" that you've suggested above such as butter, margarine, mozzarella cheese, and for that matter, fruits, vegetables, and deli-meats, are not "supplemental" at all; in fact, they are specious and lack evidence that supports their validity as a terminal ballistic test medium that correlates with human tissue.

The clear, synthetic gel product, with its frequent changes in composition and component sourcing, is also unsuitable not only for the undocumented changes in its formulation but also for the failure of the manufacturer(s) of these products to provide information on how these changes in composition and source compare against previous iterations of their product(s).

Modeling terminal ballistic performance in fluids/liquids requires more than matching density (ρ) to achieve dynamic equivalence with soft tissue. In order to properly represent terminal performance in soft tissue, the candidate fluid/liquid must also possess the same bulk modulus (K) and internal sonic velocity (c) which are all related to one another in the Newton-LaPlace formula— c = √(K/ρ)

The internal speed of sound in isopropyl "rubbing" alcohol, C3H8O, is c = 1,205 ms-1, its density is ρ = 786 kg/m³ so by extension of the Newton-LaPlace formula, its bulk modulus is K = 1.141 GPa.

Compared to the respective values of c, ρ, and K in water, 10% ordnance gelatin, and human soft tissue—

H2O: c = 1,497 ms-1, ρ = 999.87 kg/m³, K = 2.24 GPa
10% ordnance gelatin: c = 1,494 ms-1, ρ = 1,040.00 kg/m³, K = 2.32 GPa
Typical values for human soft tissue: c = 1,540 ms-1, ρ = 1,020 kg/m³, K = 2.42 GPa

—isopropyl alcohol does not compare favorably with any of these materials' values and therefore is not an acceptable candidate fluid (mixed with water or by itself) for modeling terminal ballistic response as it occurs in human tissue. No such research suggesting otherwise exists.

Due to the frequent and unknown changes in its formulation, it is also difficult to ascertain values of c, ρ, and K of the clear, synthetic gel. The only physical property of the clear, synthetic gel that is known has been subject to some variance at different times within the same source ranging from 790 kg/m³ - 824 kg/m³ with no known values for either its internal sonic velocity or bulk modulus.

Given the lack of supporting research that "ensures the consistency" of any of the "different media" that you've suggested, their use is likely to yield dubious data at best. At worst, relying on that data leads to inaccurate, and possibly dangerous, conclusions being drawn about the ammunition tested in those uncorrelated mediums.

Thanks for this post. You don't even have to check the math to see your point, it's pretty clear and well laid out.

And thanks to DocGKR also for pointing out that the search goes on for better test mediums.

I've been a ballistic geek wannabe since the '80s...

[JAD]

That's true if mixing data. Here the data is siloed. If a bullet passes traditional fbi/iwba tests, then it is supposedly good to go, right? So what difference is it to John Moses Browning if I subselect only those with blue primer sealant or only those that expand when shot through a cantaloupe?
A silo full of shit still stinks at half a mile.

[0ddl0t]

Within reason (e.g. shooting water not ice), the properties that affect expansion are density & velocity. For this supplemental test I'm not interested in correlating penetration depth, just checking for a robust margin of expansion.

I knew I'd read the above somewhere, but it took me until now to find the source:



Penetration of a 9mm bullet at 1000 ft/sec is resisted by an inertial force of about 800 pounds; it is obvious that the presence or absence of a 3 to 5 pound shear force makes no practical difference in the penetration at this velocity. This also explains why the fact that gelatin fractures more easily than tissue does is not important.

The extension of these dynamics to soft tissue variation is obvious. Different types of tissue present different resistance to finger probing by a surgeon, but the surgeon is not probing at 1000 ft/sec. Different tissue types do have differences in the amount of shear force they will support, but all of these forces are so small relative to inertial forces that there is no practical difference. The tissue types are closer to one another than they are to water, and bullet expansion in water and tissue are nearly identical at velocities over 600 ft/sec where all bullet expansion takes place (See Bullet Penetration for a detailed explanation of bullet expansion dynamics).

Since inertial forces depend on accelerating mass, it makes sense that these forces should be lower at lower velocities (because the penetrated material cannot be accelerated to a velocity higher than the bullet). Shear forces have little velocity dependence, and as a result, shear forces are a much larger fraction of the total when bullet velocity is below the cavitation threshold. This low velocity effect is the reason that total bullet penetration depth is much different in water and in tissue or a valid tissue simulant.

As a result of the penetration dynamics, most soft solids with a density very near soft tissues (i.e., near the density of water) are satisfactory tissue simulants when shear forces are not important. However, total penetration depth depends significantly on dynamics at velocities below 400 ft/sec, so most materials do not properly simulate penetration depth. The total bullet penetration depth in tissue and a valid tissue simulant should be the same; standard practice is to use calibrated gelatin to insure this. In effect, gelatin calibration is done to ensure that the shear forces in the gelatin are the same as in typical soft tissue (as described in Bullet Penetration, the technical parameter used in the dynamic is viscosity).

-- “Wound Ballistics Misconceptions.” (Duncan MacPherson, Wound Ballistics Review, 2(3): 1996; 42-43)


...Just posting for those lurking 3rd parties with open minds...

[the Schwartz]

The bolded portion of the quoted text—


I knew I'd read the above somewhere, but it took me until now to find the source:



Penetration of a 9mm bullet at 1000 ft/sec is resisted by an inertial force of about 800 pounds; it is obvious that the presence or absence of a 3 to 5 pound shear force makes no practical difference in the penetration at this velocity. This also explains why the fact that gelatin fractures more easily than tissue does is not important.

The extension of these dynamics to soft tissue variation is obvious. Different types of tissue present different resistance to finger probing by a surgeon, but the surgeon is not probing at 1000 ft/sec. Different tissue types do have differences in the amount of shear force they will support, but all of these forces are so small relative to inertial forces that there is no practical difference. The tissue types are closer to one another than they are to water, and bullet expansion in water and tissue are nearly identical at velocities over 600 ft/sec where all bullet expansion takes place (See Bullet Penetration for a detailed explanation of bullet expansion dynamics).

Since inertial forces depend on accelerating mass, it makes sense that these forces should be lower at lower velocities (because the penetrated material cannot be accelerated to a velocity higher than the bullet). Shear forces have little velocity dependence, and as a result, shear forces are a much larger fraction of the total when bullet velocity is below the cavitation threshold. This low velocity effect is the reason that total bullet penetration depth is much different in water and in tissue or a valid tissue simulant.

As a result of the penetration dynamics, most soft solids with a density very near soft tissues (i.e., near the density of water) are satisfactory tissue simulants when shear forces are not important. However, total penetration depth depends significantly on dynamics at velocities below 400 ft/sec, so most materials do not properly simulate penetration depth. The total bullet penetration depth in tissue and a valid tissue simulant should be the same; standard practice is to use calibrated gelatin to insure this. In effect, gelatin calibration is done to ensure that the shear forces in the gelatin are the same as in typical soft tissue (as described in Bullet Penetration, the technical parameter used in the dynamic is viscosity).

-- “Wound Ballistics Misconceptions.” (Duncan MacPherson, Wound Ballistics Review, 2(3): 1996; 42-43)


...Just posting for those lurking 3rd parties with open minds...

—does not affirm the validity of relying upon "lower-than-water-density" test mediums. In fact, because they misrepresent maximum terminal penetration depth, the bolded text that you've quoted above is actually an indictment of the use of "lower-than-water-density" test mediums since the accurate representation of maximum terminal penetration depth is one of the most important metrics considered when undertaking such testing.

More specifically, the mass densities of the clear, synthetic gel (790 - 824 kg/m³), butter, margarine, and mozzarella cheese are all far enough below that of water that they do not qualify as having "a density very near soft tissues" or "near the density of water". If anyone wishes to substantiate the dynamic equivalence of these "alternative test mediums", then it is incumbent upon those claiming "validity" to support that position. This is easily accomplished by supplying the respective bulk moduli (K), mass densities (ρ), and internal sonic velocities (c) so that the respective physical properties of these "alternative test mediums" may be evaluated against those of human soft tissue (c = 1,540 ms-1, ρ = 1,020 kg/m³, K = 2.42 GPa) using the physical relationship that is set forth in the Newton-LaPlace formula: c = √(K/ρ) .

Of course, you are free to provide the respective mass-densities, bulk moduli, and internal sonic velocities of these "alternative test mediums" in support of your assertion that they are indeed "valid".

If you cannot support your assertion with these physical parameters, then all you are really doing is debating in a vacuum.

[the Schwartz]

I knew I'd read the above somewhere, but it took me until now to find the source:



Penetration of a 9mm bullet at 1000 ft/sec is resisted by an inertial force of about 800 pounds; it is obvious that the presence or absence of a 3 to 5 pound shear force makes no practical difference in the penetration at this velocity. This also explains why the fact that gelatin fractures more easily than tissue does is not important.

The extension of these dynamics to soft tissue variation is obvious. Different types of tissue present different resistance to finger probing by a surgeon, but the surgeon is not probing at 1000 ft/sec. Different tissue types do have differences in the amount of shear force they will support, but all of these forces are so small relative to inertial forces that there is no practical difference. The tissue types are closer to one another than they are to water, and bullet expansion in water and tissue are nearly identical at velocities over 600 ft/sec where all bullet expansion takes place (See Bullet Penetration for a detailed explanation of bullet expansion dynamics).

Since inertial forces depend on accelerating mass, it makes sense that these forces should be lower at lower velocities (because the penetrated material cannot be accelerated to a velocity higher than the bullet). Shear forces have little velocity dependence, and as a result, shear forces are a much larger fraction of the total when bullet velocity is below the cavitation threshold. This low velocity effect is the reason that total bullet penetration depth is much different in water and in tissue or a valid tissue simulant.

As a result of the penetration dynamics, most soft solids with a density very near soft tissues (i.e., near the density of water) are satisfactory tissue simulants when shear forces are not important. However, total penetration depth depends significantly on dynamics at velocities below 400 ft/sec, so most materials do not properly simulate penetration depth. The total bullet penetration depth in tissue and a valid tissue simulant should be the same; standard practice is to use calibrated gelatin to insure this. In effect, gelatin calibration is done to ensure that the shear forces in the gelatin are the same as in typical soft tissue (as described in Bullet Penetration, the technical parameter used in the dynamic is viscosity).

-- “Wound Ballistics Misconceptions.” (Duncan MacPherson, Wound Ballistics Review, 2(3): 1996; 42-43)


...Just posting for those lurking 3rd parties with open minds...

Additionallly, submitted for the consideration of those "lurking 3rd parties with open minds", they might also wish to bear in mind that the next line after that which has been bolded in black, which has now been set in bold red, also affirms that "the total bullet penetration depth in tissue and a valid tissue simulant should be the same" and that "standard practice is to use calibrated gelatin to insure this".

Finally, if the proper representation of total bullet penetration depth is not desired, anyone can simply fire bullets into water to cause them to expand. There is no need to "reinvent the wheel" when water (which already possesses the requisite physical properties) is so easy to use and meets the requirement for being "near the density of water" or having "a density very near soft tissues".

[0ddl0t]

The bolded portion of the quoted text—



—does not affirm the validity of relying upon "lower-than-water-density" test mediums. In fact, because they misrepresent maximum terminal penetration depth, the bolded text that you've quoted above is actually an indictment of the use of "lower-than-water-density" test mediums since the accurate representation of maximum terminal penetration depth is one of the most important metrics considered when undertaking such testing.
Straw man again... No one here is arguing about obtaining valid penetration data from other media.


More specifically, the mass densities of the clear, synthetic gel (790 - 824 kg/m³), butter, margarine, and mozzarella cheese are all far enough below that of water that they do not qualify as having "a density very near soft tissues"

Patently false.

Lung (inflated): 255-604 kg/m^3
Fat: 812-964 kg/m^3
Connective tissue 911-1142
Blood is 1050
Lung (deflated): 1050
Cartilage is 1100
Intervertebral disc 1100
Larynx 1100
Bronchi 1050-1147
Liver 1050-1158
Muscle 1041-1178

https://itis.swiss/virtual-population/tissue-properties/database/density/

Rubbing alcohol 790
Ammonia (max concentration) 880
Butter is 911
Cream chesse is 966
Jello is 980-1050
Milk is 1030
Orange juice is 1050-1125
potato 1090
mozzarella is 1100
Bleach (12.5%) 1200
Salt water (saturated) 1360



Finally, if the proper representation of total bullet penetration depth is not desired, anyone can simply fire bullets into water to cause them to expand.
Bullets traveling just over their expansion thresholds for living tissue will expand readily in water, even if they are inconsistent in tissue.

But if a bullet expands in both rubbing alcohol and bleach - now you can be a bit more confident in the robustness of expansion through the variety of tissue densities it might encounter.

[the Schwartz]

No one here is arguing about obtaining valid penetration data from other media.

What is the point of any of this?

Terminal ballistic testing conducted in an uncontrolled/uncorrelated medium produces expansion and penetration data that is only comparable within the uncontrolled/uncorrelated medium and that is incomparable to all other mediums.

It is interesting to note that you continue to refuse to provide the other requisite physical parameters (that is, the respective bulk moduli, internal sonic velocities of butter, margarine, mozzarella cheese) required to support your claim that any of these—


Rubbing alcohol 790
Ammonia (max concentration) 880
Butter is 911
Cream chesse is 966
Jello is 980-1050
Milk is 1030
Orange juice is 1050-1125
potato 1090
mozzarella is 1100
Bleach (12.5%) 1200

—are valid terminal ballistic test mediums.

Once again, mass-density is just one part of the the Newton-LaPlace formula: c = √(K/ρ) . You'll need to provide all of the requisite physical properties of these "alternative mediums" to prove that they possess the dynamic equivalent qualities specified by the Newton-LaPlace formula so that they yield data comparable to other mediums.


But if a bullet expands in both rubbing alcohol and bleach - now you can be a bit more confident in the robustness of expansion through the variety of tissue densities it might encounter.

No, you cannot. What occurs in those mediums applies only within those mediums.

All that you have done so far is post the densities of various substances and refused to provide the physical parameters that would confirm their dynamic equivalence to any other medium (or human soft tissue) and support your claims.

[0ddl0t]

What is the point of any of this?
...

My point is that the existing tests of 10% gel & 10% gel behind 4 layers of denim are imperfect for many of the popular concealed carry guns on the market. Repeatable tests in other media or with alternate intermediate barriers can illustrate real deficiencies left uncovered by these traditional tests.

As an example, I give the gold dot 147 from a 3" barrel which is on Doc's list of recommended ammo and which reliably expands in traditional testing with 10% ordnance gel. But if you lower ρ (using lower density media) or V (by adding distance, barriers, etc) even slightly it begins to fail to expand.

That gold dot 147s are at the lower bounds of their performance window from a 3" barrel is useful information to know & that information can be reliably and repeatedly discerned from non traditional (but scientifically valid) tests.




Once again, mass-density is just one part of the the Newton-LaPlace formula: c = √(K/ρ) . You'll need to provide all of the requisite physical properties of these "alternative mediums" to prove that they possess the dynamic equivalent qualities specified by the Newton-LaPlace formula so that they yield data comparable to other mediums.

No. I don't. I am not attempting to compare expansion size or penetration depth between dissimilar media. I am doing a Y/N expansion check to help ensure my 147gr jhp doesn't fail to expand if shot from a 3" barrel into a 350 lb man.

Again:


Penetration of a 9mm bullet at 1000 ft/sec is resisted by an inertial force of about 800 pounds; it is obvious that the presence or absence of a 3 to 5 pound shear force makes no practical difference in the penetration at this velocity. This also explains why the fact that gelatin fractures more easily than tissue does is not important.

The extension of these dynamics to soft tissue variation is obvious. Different types of tissue present different resistance to finger probing by a surgeon, but the surgeon is not probing at 1000 ft/sec. Different tissue types do have differences in the amount of shear force they will support, but all of these forces are so small relative to inertial forces that there is no practical difference. The tissue types are closer to one another than they are to water, and bullet expansion in water and tissue are nearly identical at velocities over 600 ft/sec where all bullet expansion takes place (See Bullet Penetration for a detailed explanation of bullet expansion dynamics).

Since inertial forces depend on accelerating mass, it makes sense that these forces should be lower at lower velocities (because the penetrated material cannot be accelerated to a velocity higher than the bullet). Shear forces have little velocity dependence, and as a result, shear forces are a much larger fraction of the total when bullet velocity is below the cavitation threshold. This low velocity effect is the reason that total bullet penetration depth is much different in water and in tissue or a valid tissue simulant.

As a result of the penetration dynamics, most soft solids with a density very near soft tissues (i.e., near the density of water) are satisfactory tissue simulants when shear forces are not important. However, total penetration depth depends significantly on dynamics at velocities below 400 ft/sec, so most materials do not properly simulate penetration depth. The total bullet penetration depth in tissue and a valid tissue simulant should be the same; standard practice is to use calibrated gelatin to insure this. In effect, gelatin calibration is done to ensure that the shear forces in the gelatin are the same as in typical soft tissue (as described in Bullet Penetration, the technical parameter used in the dynamic is viscosity).

-- “Wound Ballistics Misconceptions.” (Duncan MacPherson, Wound Ballistics Review, 2(3): 1996; 42-43)

Distilled:
When a bullet is expanding, the inertial forces (velocity + density) are so very much larger than the shear forces that the shear forces can be ignored.

[the Schwartz]

My point is that the existing tests of 10% gel & 10% gel behind 4 layers of denim are imperfect for many of the popular concealed carry guns on the market. Repeatable tests in other media or with alternate intermediate barriers can illustrate real deficiencies left uncovered by these traditional tests.

As an example, I give the gold dot 147 from a 3" barrel which is on Doc's list of recommended ammo and which reliably expands in traditional testing with 10% ordnance gel. But if you lower ρ (using lower density media) or V (by adding distance, barriers, etc) even slightly it begins to fail to expand.

That gold dot 147s are at the lower bounds of their performance window from a 3" barrel is useful information to know & that information can be reliably and repeatedly discerned from non traditional (but scientifically valid) tests.

This is not correct. Since BBI already addressed this inaccuracy in post #22, I'll not bother re-posting it here. I am sure that you can locate his post for review at your convenience.




I am not attempting to compare expansion size or penetration depth between dissimilar media.

Actually, you are doing just that when you admit that you comparing expansion size in dissimilar mediums (namely the 350-pound man vs whatever uncorrelated test medium you are advocating the use of), right here—


I am doing a Y/N expansion check to help ensure my 147gr jhp doesn't fail to expand if shot from a 3" barrel into a 350 lb man.


Other than your posting of the densities of various liquids and soft solids, I am unconvinced that there is a meaningful point to any of this.

[0ddl0t]

This is not correct. Since BBI already addressed this inaccuracy in post #22, I'll not bother re-posting it here. I am sure that you can locate his post for review at your convenience.

And I've already addressed his response.




Actually, you are doing just that when you admit that you comparing expansion size in dissimilar mediums (namely the 350-pound man vs whatever uncorrelated test medium you are advocating the use of), right here—
Nowhere in this thread do I suggest comparing expansion size (or penetration depth). I'm talking about a Y/N validation for whether a bullet expands at all.



Other than your posting of the densities of various liquids and soft solids, I am unconvinced that there is a meaningful point to any of this.
As am I with continuing this conversation.

[DocGKR]

Wow....I am stuck working 12+ hours a day and come back to see this mess.

First--every institution I am aware of that conducts valid terminal ballistic testing for LE and mil purposes performs correlation with shots in living tissue. So far I am unaware of any such valid analysis being performed with clear synthetic test media.

Second--every institution I am aware of that conducts valid terminal ballistic testing for LE and mil purposes regularly tests alternative tissue simultants, including clear synthetic test media, to see if new advances offer a more effective option than 10% ordnance gel. So far I am unaware of any simulant which has proven to offer superior terminal performance results in the lab than properly fabricated and validated 10% ordnance gelatin.

Third--like some other projectiles we have tested, including early versions of Gold Dot, Ranger Talon, HST, some lots of G2 had manufacturing QC issues which proved to inhibit bullet terminal performance..........want to guess how these problems were discovered??? (Hint: see photo below showing top row of failed G2 fired through 4LD compared to known control loads)

44880

[Sigfan26]

Wow....I am stuck working 12+ hours a day and come back to see this mess

I’d actually like to thank you for this alone. Folks at trauma hospitals do not get the respect they deserve.


Sent from my iPhone using Tapatalk

[DocGKR]

Also--we typically have done the majority of our pistol ammunition testing out of 4" barrels, but generally see minimal difference in terminal performance results in barrels from 3.5-5".

The IWBA published some of Gene Wolberg’s initial data on his study of San Diego PD officer involved shootings; he later presented more at an IWBA Conference in Sacramento. When I last spoke with Mr. Wolberg in May of 2000, he had collected data on nearly 150 officer involved shootings which showed the majority of the 9mm 147 gr bullets fired by officers had penetrated 13 to 15 inches and expanded between 0.60 to 0.62 inches in both human tissue and 10% ordnance gelatin. The first third of Mr. Wolberg’s groundbreaking study assessed the SDPD standard issue Winchester 147 gr JHP. SDPD then switched to the Federal 147 gr JHP, so the remaining 2/3 rds of officer involved shooting incidents assessed by Mr. Wolberg used the Federal loading. Interestingly both the Federal and Winchester 147 gr loadings demonstrated the same close correlation between laboratory testing and actual terminal performance in tissue. In Mr. Wolberg’s study, the OIS incident bullet penetration depths are the actual total length of the bullet track in tissue, as measured by the Medical Examiner at autopsy.

[DocGKR]

Sigfan26--Thank you! That is refreshing to hear, especially since some ignorant folks insisted that I am "just a dentist"...

[Sigfan26]

Sigfan26--Thank you! That is refreshing to hear, especially since some ignorant folks insisted that I am "just a dentist"...

Lol. My brother is an anesthesiologist that works more hours a week than I do. Doctors are under appreciated!


Sent from my iPhone using Tapatalk

[the Schwartz]

Wow....I am stuck working 12+ hours a day and come back to see this mess.

First--every institution I am aware of that conducts valid terminal ballistic testing for LE and mil purposes performs correlation with shots in living tissue. So far I am unaware of any such valid analysis being performed with clear synthetic test media.

Second--every institution I am aware of that conducts valid terminal ballistic testing for LE and mil purposes regularly tests alternative tissue simultants, including clear synthetic test media, to see if new advances offer a more effective option than 10% ordnance gel. So far I am unaware of any simulant which has proven to offer superior terminal performance results in the lab than properly fabricated and validated 10% ordnance gelatin.

Third--like some other projectiles we have tested, including early versions of Gold Dot, Ranger Talon, HST, some lots of G2 had manufacturing QC issues which proved to inhibit bullet terminal performance..........want to guess how these problems were discovered??? (Hint: see photo below showing top row of failed G2 fired through 4LD compared to known control loads)

44880

Thanks for all that you've done here, Doc. Nice to have another voice of reason here. Found, I think, the test data for the image above to be interesting.

[DocGKR]

I am on 24 hour call today and don't know where that data is at the moment--it is not on my current computer. We just finished a kid with a maxillary fracture from a bike accident, are working up an older adult who will need surgery for their bicycle induced orofacial injures, as well as trying to get OR time for a person with a jaw tumor, so I am unsure when I will be able to look for that information

Our service has never been busier and I have not had less than a 12 hour day in months, with many extending to 18 hours--have very little time for other endeavors at the moment.

[the Schwartz]

I am on 24 hour call today and don't know where that data is at the moment--it is not on my current computer. We just finished a kid with a maxillary fracture from a bike accident, are working up an older adult who will need surgery for their bicycle induced orofacial injures, as well as trying to get OR time for a person with a jaw tumor, so I am unsure when I will be able to look for that information.

Our service has never been busier and I have not had less than a 12 hour day in months--with many extending to 18 hours.


No problem, Doc. I am digging around here and will locate it. Take care of yourself and get some rest.


ETA: OK, think that I located the associated data:

9 mm Speer 147 gr G2 at 955 fps (accuracy 95-0x):
BG: Pen = 13.8”, RD = 0.53”, RL = 0.45”, RW = 147.5 gr
4LD: Pen = 20+”, RD = 0.35”, RL = 0.65”, RW = 147.0 gr (all rounds failed to expand)
AG: Pen = 10.5”, RD = 0.65”, RL = 0.54”, RW = 147.5 gr

[Sigfan26]

I am on 24 hour call today and don't know where that data is at the moment--it is not on my current computer. We just finished a kid with a maxillary fracture from a bike accident, are working up an older adult who will need surgery for their bicycle induced orofacial injures, as well as trying to get OR time for a person with a jaw tumor, so I am unsure when I will be able to look for that information

Our service has never been busier and I have not had less than a 12 hour day in months, with many extending to 18 hours--have very little time for other endeavors at the moment.

Lots of folks need you more than us. Thanks for all the work you do.


Sent from my iPhone using Tapatalk

[CZ Man]

Part 2 of the article is posted. But don't expect to see any results. This author is saving the results for a 3rd article. :mad:

https://www.policeone.com/police-products/firearms/accessories/ammunition/articles/ballistic-gelatin-comparisons-part-ii-NVdpfONSxRFxBwTL/

[Nightvisionary]

I am curious if part of the penetration discrepancy between Clear Gel and ballistic gelatin is related to the temperature of the medium. Ballistic gelatin is chilled to 39F while Clear Gel is used at whatever the ambient air temperature is at it's storage and testing location. Could temperature differences in Clear Gel also explain variations in different Clear Gel tests I have seen? One specific test that comes to mind is MrGunsnGear test of Federal 130 HST +P 38 Special in Clear Gel exhibited 16 inches of penetration with a J frame while my own Clear Gel test with a Ruger LCR gave 11.75 inches of penetration (Which is identical to the only calibrated Vyse 10% ballistic gelatin test I have found for this round, posted on M4C). I have two 16 inch Clear Gel blocks so I will refrigerate one and see if there is a difference in penetration.

[paherne]

Wow. Just saw this thread and read the two articles. I need to start writing, just to balance out the wackadoo factor.

[DocGKR]

Could temperature differences in Clear Gel also explain variations in different Clear Gel tests I have seen?

Unlikely, as they are entirely different materials with different chemical and physical properties compared to organically derived ordnance gelatin.

[the Schwartz]

Part 2 of the article is posted. But don't expect to see any results. This author is saving the results for a 3rd article. :mad:

https://www.policeone.com/police-products/firearms/accessories/ammunition/articles/ballistic-gelatin-comparisons-part-ii-NVdpfONSxRFxBwTL/

Thanks for the link, CZ Man.

Of the information presented in that linked article, the part that I find most "telling" is the following paragraph in which the author describes the glaring difference in terminal behavior of the exact same round, fired under the exact same conditions:


In Hornady’s tests of its 9mm +P, 135 grain, Critical Duty Flexlock bullet, the projectile normally penetrated around 14.5 inches in bare, calibrated gelatin. Independent testing of this projectile by the US Department of Homeland Security (14 inches) and the FBI (14 inches), as well as joint Hornady/agency testing with the Mesa (Arizona) Police Department (14 inches), Nebraska State Patrol (14.75 inches) and the Texas Department of Public Safety (14.25 inches), validated this performance (using a variety of pistol makes and barrel lengths) and confirmed Hornady’s expectation for this projectile. However, when Hornady tested the same ammunition in the clear, synthetic gelatin substitute (same test protocol and conditions, including barrel length and lack of an intermediate barrier) the 9mm FlexLock bullet penetrated around 19 inches. This represented a 31% increase in penetration in the clear synthetic product compared to FBI-calibrated gelatin.

To put a finer point on this issue, I quote a particularly relevant portion of a post made earlier in this thread by Dr. Roberts:


Second--every institution I am aware of that conducts valid terminal ballistic testing for LE and mil purposes regularly tests alternative tissue simulants, including clear synthetic test media, to see if new advances offer a more effective option than 10% ordnance gel. So far I am unaware of any simulant which has proven to offer superior terminal performance results in the lab than properly fabricated and validated 10% ordnance gelatin.

Concisely put, based upon Dr. Roberts' comprehensive experience and input, I doubt that anything ground-breaking is going to emerge from the third part of the article that has not already been demonstrated by at least three other independent sources who have also evaluated Clear Ballistics Gel against validated 10% ordnance gelatin: the Clear Ballistics Gel product is simply not suitable for use as a valid tissue simulant.

[DocGKR]

Correct.

Also, keep in mind that ordnance gel blocks are "validated", not "calibrated".....

[BBMW]

I don't know if anyone still cares, and I just flipped through the thread and didn't see it posted. Here's part 2. Hint: for results, wait for part 3

https://www.policeone.com/police-products/firearms/accessories/ammunition/articles/ballistic-gelatin-comparisons-part-ii-NVdpfONSxRFxBwTL/

[SiriusBlunder]

Part 3 (https://www.policeone.com/police-products/firearms/accessories/ammunition/articles/ballistic-gelatin-comparisons-part-iii-IbjkEYB93TAd5o6J/)


IMPLICATIONS

With respect to the tested product, our results suggest the following implications:


The clear synthetic gelatin must be calibrated by the user before use.

The factory warranty cards cannot be relied upon to give an accurate measure of the product’s calibration.


The clear synthetic gelatin currently demonstrates a tendency to limit bullet expansion and increase bullet penetration, compared to FBI-standard, 10% calibrated organic gelatin.

Based on our limited sample, this tendency seems to apply irrespective of bullet manufacturer, materials, design, construction, weight, pressure, or velocity. It seems that bullets penetrate significantly more in the clear synthetic, even when acceptable variations in organic gelatin penetration depth are accounted for.


The clear synthetic gelatin currently does not appear to be a suitable substitute for FBI-standard, 10% calibrated organic gelatin if the bullets will be measured and evaluated according to FBI performance standards.

Because the bullets we tested behaved so differently in the clear synthetic gelatin versus the 10% calibrated organic gelatin, it’s not appropriate to use the FBI standards ‒ which were designed to be applied to 10% calibrated organic gelatin – to measure bullet performance in the clear synthetic product.

In example, it’s inappropriate to measure and evaluate bullet penetration according to the FBI protocol (which rewards bullets that penetrate between 12” and 18” in 10% calibrated gelatin and penalizes those that fall outside this window) when bullets may routinely penetrate an extra 6” in the clear synthetic. If we did apply FBI standards to the clear synthetic, we might “pass” a bullet that normally fails the FBI protocol because it doesn’t penetrate deeply enough. Conversely, we might “fail” a bullet because it over penetrates in the clear synthetic, even when it normally passes the FBI protocol because by remaining within FBI penetration limits.


There is no apparent “conversion” between data derived from 10% organic gelatin and the current version of the clear synthetic.

Unfortunately, our limited test doesn’t indicate a conversion “shortcut” is likely. It would be convenient if we could develop a conversion factor that would equate the organic gelatin and clear synthetic gelatin, but our data indicate that bullet performance is too variable in these mediums to develop a universal “rule of thumb.” Perhaps a skilled mathematician could derive a constant from a more complete sample, but we’re not seeing one lurking in the data.

[CZ Man]

Can anybody recommend a BB gun to use for calibration/ validating a gel block at the required 590 fps? I don't have a chronograph to check speeds, so I'm unsure of which model to choose from.

[Wayne Dobbs]

Can anybody recommend a BB gun to use for calibration/ validating a gel block at the required 590 fps? I don't have a chronograph to check speeds, so I'm unsure of which model to choose from.

You have to have a chronograph to ascertain velocity of the BB. There's a chart to compare actual velocities to actual block penetration of the BB to make sure the gel block is compliant. I think the Crossman 760 is the popular test BB gun for this, but I'm sure there are others that work just fine.

[the Schwartz]

It appears that Part 3 has been published:

https://www.policeone.com/police-products/firearms/accessories/ammunition/articles/ballistic-gelatin-comparisons-part-iii-IbjkEYB93TAd5o6J/

The following conclusions, some of them oddly phrased, are made in the article:

1.The clear synthetic gelatin must be calibrated by the user before use.

2. The clear synthetic gelatin currently demonstrates a tendency to limit bullet expansion and increase bullet penetration, compared to FBI-standard, 10% calibrated organic gelatin.

3. The clear synthetic gelatin currently does not appear to be a suitable substitute for FBI-standard, 10% calibrated organic gelatin if the bullets will be measured and evaluated according to FBI performance standards.

4. There is no apparent “conversion” between data derived from 10% organic gelatin and the current version of the clear synthetic.

[CZ Man]

You have to have a chronograph to ascertain velocity of the BB. There's a chart to compare actual velocities to actual block penetration of the BB to make sure the gel block is compliant. I think the Crossman 760 is the popular test BB gun for this, but I'm sure there are others that work just fine.

OK. Thanks for the suggestion.
I take it the Crossman 760 doesn't reliably shoot at 600 fps. Hence the need for the chronograph to verify speed?

[0ddl0t]

OK. Thanks for the suggestion.
I take it the Crossman 760 doesn't reliably shoot at 600 fps. Hence the need for the chronograph to verify speed?

The FBI specification is a steel BB at 590 +/- 15 fps. You'll probably need to play around with the # of pumps and distance from muzzle to reliably shoot 575-605fps.

[the Schwartz]

Part 3 (https://www.policeone.com/police-products/firearms/accessories/ammunition/articles/ballistic-gelatin-comparisons-part-iii-IbjkEYB93TAd5o6J/)

Unfortunately, our limited test doesn’t indicate a conversion “shortcut” is likely. It would be convenient if we could develop a conversion factor that would equate the organic gelatin and clear synthetic gelatin, but our data indicate that bullet performance is too variable in these mediums to develop a universal “rule of thumb.” Perhaps a skilled mathematician could derive a constant from a more complete sample, but we’re not seeing one lurking in the data.



While it "might" be possible to derive a scaling constant that "converts" test data for non-expanding/non-deforming projectiles obtained in Clear Ballistics Gel to its equivalent in 10% ordnance gelatin, due to the tendency of CBG to under-drive expansion and over-represent terminal penetration of expanding designs such a scheme is simply not plausible for the projectile designs that are best suited for self-defense.

Also, not sure how I missed your posting of the publication of Part 3 of the series DMWINCLE...apologies as I wasn't aware of your post prior to mine bringing this to light. I reckon that this is what I get for not reviewing these threads as thoroughly as I could/should.

[SiriusBlunder]

Also, not sure how I missed your posting of the publication of Part 3 of the series DMWINCLE...apologies as I wasn't aware of your post prior to mine bringing this to light. I reckon that this is what I get for not reviewing these threads as thoroughly as I could/should.

No need to apologize, but thanks. Better to have too many links to the conclusion than none. :-)

I was glad to see he pulled no punches in his summary.