An attempt at math: clear vs. organic

[No.6]

Posting this with a little trepidation as obviously there's tons of experience here ... but even if this doesn't add to the body of knowledge but only confirms what's already known, perhaps commentary can clarify avenues for further inquiry.

As noted here and many other places, clearly (pun) the cleargel is not a 1:1 map to calibrated organic gel despite its claims. I got my own introduction to that *after* indulging my data science fervor by collecting 300+ of other people's test results from around the web -- now 352 thanks to recent 5pins postings.

The PoliceOne series of articles didn't find a formula for translating 'clear' results to organic. I wondered if, having all this data lying about, one could be suggested (because the non-professional largely only has the YouTube-y resources to draw on).

Fortunately I saved URLs on each sample, and so went back and labeled each as a result from clear or from organic, then did more graphing.

Caveats:
- This is that same .380 ACP data I'd posted in the G42 thread and is not intended to suggest that .380 ACP is going to turn into unicorn farts. I collected this data originally because 380 is not powerful and was therefore interesting. For 9/40/45 the smart mind wouldn't grind through 300 YouTube videos just to select what Doc already recommended (or at least I think it smart to just go with his list).
- As was written in the thread about 5pins' XTP test, there is currently little (publicly posted) data in organic.
- Nothing in the post seems to suggest that, if there's a clear-to-organic linear regression lurking, that the same would work for other calibers.

Finally, the only conclusion I'd be prepared to stand on from the available data (to me) at this time is (big shock) yep, clear gel definitely does not represent results one will get in organic.

That said: Organic vs. Clear

[Nephrology]

You're waaaaaaaaay overthinking all of this.

[OlongJohnson]

Lots of smart people have studied it and found there is no correlation. Results are understood to be nonlinear on several variables.

Good enough for me to not spend a lot of time trying to do what people with more letters after their name and better access to data haven't been able to do.

[the Schwartz]

Posting this with a little trepidation as obviously there's tons of experience here ... but even if this doesn't add to the body of knowledge but only confirms what's already known, perhaps commentary can clarify avenues for further inquiry.

As noted here and many other places, clearly (pun) the cleargel is not a 1:1 map to calibrated organic gel despite its claims. I got my own introduction to that *after* indulging my data science fervor by collecting 300+ of other people's test results from around the web -- now 352 thanks to recent 5pins postings.

The PoliceOne series of articles didn't find a formula for translating 'clear' results to organic. I wondered if, having all this data lying about, one could be suggested (because the non-professional largely only has the YouTube-y resources to draw on).

Fortunately I saved URLs on each sample, and so went back and labeled each as a result from clear or from organic, then did more graphing.

Caveats:
- This is that same .380 ACP data I'd posted in the G42 thread and is not intended to suggest that .380 ACP is going to turn into unicorn farts. I collected this data originally because 380 is not powerful and was therefore interesting. For 9/40/45 the smart mind wouldn't grind through 300 YouTube videos just to select what Doc already recommended (or at least I think it smart to just go with his list).
- As was written in the thread about 5pins' XTP test, there is currently little (publicly posted) data in organic.
- Nothing in the post seems to suggest that, if there's a clear-to-organic linear regression lurking, that the same would work for other calibers.

Finally, the only conclusion I'd be prepared to stand on from the available data (to me) at this time is (big shock) yep, clear gel definitely does not represent results one will get in organic.

That said: Organic vs. Clear

There are several tremendous problems with the Clear Ballistics synthetic gelatin product.

Of primary concern is that the density of the Clear Ballistics synthetic gelatin product is significantly below that of the human soft tissues being replicated. Depending upon its date of manufacture, the Clear Ballistics gelatin product has a density of somewhere between 0.790 and 0.865 g/cm³. I have several samples of the Clear Ballistics synthetic gelatin product that vary widely in their density depending upon when they were acquired. This occurs because the manufacturer routinely alters the formulation of the Clear Ballistics synthetic gelatin product. The manufacturer's ''self-inflicted'' lack of consistency and physical similitude introduces a serious flaw into any testing methodology using the Clear Ballistics gelatin product because the pressure interface equation* that governs the expansion and deceleration of the projectile during its penetration—

½ρ_P(V-U)² + Y_P = ½ρ_TU² + R_T

—mandates that the pressure produced by the surrogate test medium must replicate that of the actual medium that it is representing. If the density of the surrogate test medium does not closely match the density of the actual medium for which it is being substituted, it will not replicate the pressure that the actual target medium would produce. In the case of the Clear Ballistics gelatin product, this means that the significantly lower density will under-drive expansion leading to greater penetration depths occurring than would be seen in actual human soft tissues.

Human soft tissues, namely skeletal/abdominal muscle tissues have a density range of 1.010 - 1.070 g/cm³. Correctly prepared and BB shear-validated organically-derived 10% ordnance gelatin has a density of 1.020 - 1.040 g/cm³. Water has a density, depending upon its temperature, of 0.99989 - 0.98856 g/cm³. Because 10% ordnance gelatin and water are dynamically similar—having material properties close to that of human soft tissues being modeled—the same density, internal sonic velocity, and bulk modulus of human soft tissues—they are suitable for use in controlled laboratory settings as soft tissue simulants.

Of secondary—but no less equal—concern is that the shear and strain rates of the Clear Ballistics gelatin product are considerably lower than that of soft human muscle tissue. Like human soft tissues, during projectile penetration, 10% ordnance gelatin and PAGs deform and fail under high strain rates. When considering physically associating gels like the Clear Ballistics synthetic gel product, which is made of tri-block co-polymers like polystyrene and poly-isoprene, the compressive storage and loss modulus of synthetic gels is 4 - 5 times lower than that of 10% ordnance gelatin and does not match that of human soft muscle tissue. This results in greater than actual exhibited damage along the permanent wound channel in addition to a significant reduction in resistance to the forward motion of the projectile (decelerative forces) further increasing the tendency of the Clear Ballistics synthetic gel product to over-represent projectile maximum terminal penetration depth.

This paper—

https://apps.dtic.mil/dtic/tr/fulltext/u2/a481959.pdf

—addresses in finer technical detail many of the issues that I have addressed above.

Finally, because all of these non-linear variable effects are ''tangled'' with one another, it is nigh on impossible to separate them from one another in such a manner so as to isolate the effect of each one for mathematical analyses.

John Ervin, of brassfetcher.com, is a Mechanical Engineer with extensive experience in the field who has produced a video here—

https://www.youtube.com/watch?v=5pqP...ature=emb_logo

—that illustrates (in a well-done, non-technical presentation) the futility of trying to ''untangle'' the mess that is comparing the terminal performance of projectiles in the Clear Ballistics synthetic gel product against all other test mediums.

This is what we—in the field of law-enforcement—call a 'clue'.




*in the form of the modified Bernoulli equation introduced separately and independently by V. P. Alekseevskii and A. Tate in 1967

[No.6]

There are several tremendous problems with the Clear Ballistics synthetic gelatin product....
This paper—

https://apps.dtic.mil/dtic/tr/fulltext/u2/a481959.pdf

—addresses in finer technical detail many of the issues that I have addressed above.

Finally, because all of these non-linear variable effects are ''tangled'' with one another, it is nigh on impossible to separate them from one another in such a manner so as to isolate the effect of each one for mathematical analyses.
...
This is what we—in the field of law-enforcement—call a 'clue'.

Thanks!

It's been a few decades since E&M in college, and I didn't do fluid dynamics being on the computing side, but I follow well enough.

From the data science field, one can readily agree that there's not going to be a nice multi-variate linear analysis like of old, especially given the note you included (edited out?) about the batches of cleargel not being consistent. Being accustomed to datasets with 1M+ observations involving lots of variables (personal behavior is definitely 'tangled'), "tangled" variables can still be used for predictors if one has enough data (think random forests and neural networks), but again I agree -- nobody is going to sit down and fire out 10k or 100k rounds to make a viable sample. I think the PoliceOne study had 72 rounds (3 rounds x 6 types x bare/clothed x organic/clear) and my little web scouring produced even less after filtering for brands that had results in both organic and clear.

From the mil article:

More extensive work on these and other similar material systems is planned for the future.

and that was 2006. If I can venture an opinion, it'd be that producing that poly gel product 14 years later, without addressing the issues you cite, verges on the overtly fraudulent (I'm also not an attorney). Why not still produce Pintos? It also means those of us not blessed with a government-sized lab are kind of pooched in terms of consumer research and selection. The casual reader can't (or shouldn't) even compare one set of 'clear' results to another.

Anyway again, thanks and very informative. If the dataset is of interest for whatever reason, let me know.

[the Schwartz]

Thanks!

It's been a few decades since E&M in college, and I didn't do fluid dynamics being on the computing side, but I follow well enough.

From the data science field, one can readily agree that there's not going to be a nice multi-variate linear analysis like of old, especially given the note you included (edited out?) about the batches of cleargel not being consistent. Being accustomed to datasets with 1M+ observations involving lots of variables (personal behavior is definitely 'tangled'), "tangled" variables can still be used for predictors if one has enough data (think random forests and neural networks), but again I agree -- nobody is going to sit down and fire out 10k or 100k rounds to make a viable sample. I think the PoliceOne study had 72 rounds (3 rounds x 6 types x bare/clothed x organic/clear) and my little web scouring produced even less after filtering for brands that had results in both organic and clear.

From the mil article:

More extensive work on these and other similar material systems is planned for the future.

and that was 2006. If I can venture an opinion, it'd be that producing that poly gel product 14 years later, without addressing the issues you cite, verges on the overtly fraudulent (I'm also not an attorney). Why not still produce Pintos? It also means those of us not blessed with a government-sized lab are kind of pooched in terms of consumer research and selection. The casual reader can't (or shouldn't) even compare one set of 'clear' results to another.

Anyway again, thanks and very informative. If the dataset is of interest for whatever reason, let me know.

For the most part, I agree with you about the ability to rely upon ''tangled'' variables to be used as predictors given adequate sample sizes typically n > 10⁶. The ''fly-in-the-ointment'' here is that the Clear Ballistics gel manufacturer constantly reformulates their product (which is composed of Versa-Gel co-polymer base that is plasticized by Paralux paraffinic processing oil) which alters the product's mass density and compressive storage and loss modulus every time a ''new'' formulation is released to the market.

So, even if we were to undertake the considerable time and expense of amassing a sample size of n > 10⁶ that would be large enough to ''untangle'' the ''tangled'' variables to make accurate predictions/conversions to organically-derived 10% ordnance gelatin test equivalents for every new formula that came along, we'd need to do it again for the next iteration to come along.

One of the many claims made by the Clear Ballistics gel manufacturer about their product—besides the provably false claim that their clear gel product replicates 10% ordnance gelatin results—is that it also makes testing easier and more convenient for the layman and advanced hobbyist. I suspect that very few folks would find the need to amass one or two million data points to make the conversion from the Clear Ballistics gel to 10% ordnance gelatin to be 'easy' or 'convenient' or that they'd want to repeat that every time that they obtained a batch of the Clear Ballistics gel with a 'new' formulation.

As you've noted so aptly above, ''The casual reader can't (or shouldn't) even compare one set of 'clear' results to another.''

While I appreciate the offer of your data, the two mathematical bullet penetration models that I have produced (the Q-model and mTHOR algorithm) require confirmation using test data taken only from organically-derived 10% ordnance gelatin that has been properly prepared and shear-validated. At present, I have over 900 such data in my correlative database—encompassing all projectile forms—from 15 different independent laboratory sources. Both models (the Q-model and mTHOR algorithm) allow anyone to convert terminal ballistic test results obtained by firing projectiles into water into equivalent organically-derived 10% ordnance gelatin test results.

Thank you though for the very kind offer and thought!

[No.6]

All that diligence and then there's this: https://www.pewpewtactical.com/ballistic-gel/

Rather disheartening. Maybe chicken entrails (if not pork ribs and watermelons)?

[Jared]

DocGKR has recommendations for 380 ammo here on this site. Chuck Haggard has made some posts over the years as well about decent 380 loads. I’d trust them a long way before any YouTube channel I can think of unless that YouTube channel is LTT.

I’m pretty convinced that people put way more mental effort into worrying about ammo selection as it is, and DocGKR has maxes notes to that effect in his own posts at different times.

Finally, of the various substitute mediums, I’d trust clear gel results much further than I’d trust the results of a target assembled from groceries....

[the Schwartz]

DocGKR has recommendations for 380 ammo here on this site. Chuck Haggard has made some posts over the years as well about decent 380 loads. I’d trust them a long way before any YouTube channel I can think of unless that YouTube channel is LTT.

I’m pretty convinced that people put way more mental effort into worrying about ammo selection as it is, and DocGKR has maxes notes to that effect in his own posts at different times.

Finally, of the various substitute mediums, I’d trust clear gel results much further than I’d trust the results of a target assembled from groceries....

Not that I don't ''get'' your humor....because I do...but...in all seriousness...

If using shear-validated 10% ordnance gelatin poses to much investment (time & effort), there's always using water since it is also a valid soft tissue simulant.

With any of the three mathematical bullet penetration equations that are available (Q-model, mTHOR algorithm, and MacPherson WTI) prediction of maximum penetration depth and wound cavity volume is easily accomplished. All that is required for using water as tissue simulant is a chronograph, something to hold water bags—or a dozen ½-gallon paperboard milk/juice cartons lined up nice 'n straight—a decent set of calipers, and a reloading scale to weigh the recovered bullet.

[No.6]

I’m pretty convinced that people put way more mental effort into worrying about ammo selection

The article had nothing to do with ammo selection but whatever. Secondly .380 is still not made out of magic. The only purpose was to suss out if there is any value in all these clear gel tests, and in the process I've learned the clear has changed iteratively so as to make interpreting any one result relative to others kinda pointless. At best, maybe (maybe!) the online ammo vendors might have run a bunch of tests out of one big buy of gel so their tests compare to their other contemporaneous tests. Maybe.

For my own social purposes I already have caliber and selection within Doc's list and, being a private citizen, am unlikely to need to revisit the subject on a practical basis for a long while. This is just math for educational purposes, and it worked; I've learned more in the process.