Doubts about gelatin shooting

[coylh]

As a result of some discussions about bullet performance, I started collecting
published data on gelatin shoots.  This was very interesting and I enjoyed doing
some simple statistics and playing around with Excel.

The natural inclination is to compare different cartridges or bullets, to find
out which ones are better. However, I began to be dissatisfied with some aspects
of using these gelatin tests in ranking loads.

I have along the way developed the suspicion that most gelatin results can't be 
compared to each other with precision, and that the method I was using to rank 
loads is flawed.

I've organized my complaints into sections. Most of this is quotes from 
[url]www.firearmstactical.com:[/url]  they come accross as very professional gelatin
shooters.


------------

Very few people publishing gelatin results document their data well.  Often it's
not even stated what percentage of gelatin was used.

"When gelatin is not calibrated it’s impossible to determine the validity of the
data."
-- [url]http://www.firearmstactical.com/briefs9.htm[/url]

"... gelatin consistency varies greatly with temperature and how it was made. 
The mandatory calibrating of gelatin is as fundamental to scientific method as 
verifying the accuracy of a sensitive balance with a known weight."
-- [url]http://www.firearmstactical.com/streetstoppers.htm[/url]

"A good researcher/author will publish his ordnance gelatin calibration data 
(BB velocity and penetration)."
--http://www.firearmstactical.com/briefs9.htm

"If two or more gelatin blocks are going to be lined-up end-to-end to capture 
the entire wound path of the bullet under test, each and every gelatin block 
must be calibrated ..."
-- [url]http://www.firearmstactical.com/tacticalbriefs/volume3/number2/article1.htm[/url]

It's rare to see calibration data listed and it's unheard of for testers to 
list multiple calibration data when they use two blocks of gelatin, yet it's
common to see two blocks used when penetration is deep.  

Calibration BB penetration can vary by 42%* even with the best testers, yet 
no one is correcting for calibration penetration inconsistency except 
firearmstactical (and they do so only sometimes).
* 2.91 - 4.13 inches [url]http://www.firearmstactical.com/briefs.htm[/url]


------------

"Clothed gelatin" test results use a variety of materials, thicknesses, and 
number of layers. This complicates comparison.  This however, may not be 
unrealistic; people shot will be wearing a variety of clothing. Never the 
less, it is in the spirit of gelatin testing to produce repeatable results, 
and using different test methods complicates comparison.  

"FBI Ammunition Test Protocols ... The gelatin block is covered with four 
layers of clothing: one layer of cotton T-shirt material (48 threads per 
inch); one layer of cotton shirt material (80 threads per inch); a 10 ounce 
down comforter in a cambric shell cover (232 threads per inch); and one layer 
of 13 ounce cotton denim (50 threads per inch)."
-- [url]http://www.firearmstactical.com/briefs26.htm[/url]

"... two layers of loosely layered denim."
-- [url]http://www.goldenloki.com/ammo/gel/tests.htm[/url]

"... covered by four layers of 16 ounce denim cloth."
-- [url]http://www.firearmstactical.com/briefs9.htm[/url]


------------

There are two basic measurements made in gelatin tests.  One is the final 
expanded diameter of the bullet.  Unfortunately measuring this is more 
difficult that it sounds:

"... effective expanded bullet diameter is difficult to estimate with 
useful accuracy because the expanded periphery is inevitably irregular and 
not easily related to the effective expanded diameter."
-- [url]http://www.firearmstactical.com/iwba.htm[/url]

Some bullets are so irregularly shaped that the tester provided two 
measurements*: one of the lead core and another for the jacket.
* [url]http://www.firearmstactical.com/test_data/40sw/win40-180rsxt-g27.htm[/url]

In addition, different people measure the diameter with different techniques:

"... and measured for expansion by averaging its greatest diameter with 
its least diameter."
-- [url]http://www.firearmstactical.com/briefs26.htm[/url]

"Recovered rounds were measured at multiple points and then averaged to 
account for uneven expansion."
-- [url]http://www.goldenloki.com/ammo/gel/tests.htm[/url]

"... calculated on the basis of four cross-sectional measurements of each 
bullet face."
-- Shooting Times 1997 June p52


------------

The other measurement is penetration. In otherwise similar bare gelatin 
shoots where you would expect repeatable results, the penetration is 
sometimes inconsistent, even though the values listed are averaged results.

5 shot average: .40 S&W Golden Saber 165grains@1022 = 14.8 inches of penetration and .65 caliber expansion -- [url]http://apollo.demigod.org/~zak/firearms/fbi-pistol.php[/url]
5 shot average: .40 S&W Golden Saber 165grains@1043 = 12.0 inches of penetration and .68 caliber expansion -- [url]http://www.firearmstactical.com/test_data/40sw/rem40-165gs-g27.htm[/url]

5 shot average: 9x19 Win Supreme SXT 147grains@921 = 17.6 inches of penetration and .50 caliber expansion -- [url]http://www.firearmstactical.com/test_data/9mm/win9-147ssxt-g26.htm[/url]
3 shot average: 9x19 Win Supreme SXT 147grains@912 = 13.5 inches of penetration and .53 caliber expansion -- Shooting Times 1997 June p52

5 shot average: .45 ACP Golden Saber 185grains@1037 = 14.4 inches of penetration and .72 caliber expansion -- [url]http://apollo.demigod.org/~zak/firearms/fbi-pistol.php[/url]
5 shot average: .45 ACP Golden Saber 185grains@1046 = 10.1 inches of penetration and .87 caliber expansion -- [url]http://apollo.demigod.org/~zak/firearms/fbi-pistol.php[/url]


------------

One of the units of measurement used to rank performance is Theoretical 
Hole Volume (THV). That is, imagine that the bullet destroys a cylinder 
shaped volume of tissue in the target that is as deep as the bullet penetrated,
and as wide as the bullet's final expanded diameter.

The penetration and expansion measurements which THV is derived from may 
suffer from their own problems of measurement.  However, even if these two 
measurements were perfect, the formula's theoretical measurement differs 
from reality in three ways:

a) A particular bullet doesn't crush the same amount of tissue throughout 
the length of its wound track:

"As a bullet penetrates soft tissue, it loses velocity, and this affects 
its 'effective diameter.' When the bullet first penetrates and expands, it 
is moving so quickly that it crushes almost all soft tissue it comes into 
direct contact with. However, as velocity begins to slow, soft tissue is then 
able to stretch around the smooth outer edges of the mushroom-shaped lead 
core shoulder to move out of the way. As the bullet slows further it plows 
more and more tissue aside instead of crushing it.

Near the end of the wound track, the diameter of the permanent cavity might 
be less than 60 percent of the expanded diameter of the bullet. The last few 
inches of the wound track are the most important because this is where the 
vital cardiovascular structures are located that you’re trying to damage."
--http://www.firearmstactical.com/briefs2.htm

b) Different bullet shapes inherently crush different amounts of tissue:

"A round nose FMJ bullet crushes a permanent cavity in soft tissue that 
averages approximately 66 percent of the bullet’s diameter. Whereas the 
blunt, non-aerodynamic shape of an expanded JHP bullet crushes a permanent 
cavity that averages approximately 82 percent of the bullet’s expanded 
diameter."
--http://www.firearmstactical.com/briefs23.htm

c) A bullet does not penetrate the target at its expanded diameter.  There 
is some distance, even if short, where the bullet is expanding.


These three factors make theorizing about the size of the permanent cavity 
difficult. Besides, the value of gelatin is that you can measure real 
results, not theoretical values. Why go to the significant trouble of 
gelatin testing to obtain real, measureable results, only to turn around 
and estimate in the actual ranking of performance.  Why not just measure 
the permanent cavity?

Sorry this has been so long, but I thought I would point out some aspects
of gelatin shooting that have left me with doubts about the whole process.

 

[lbmii]

Yes you are right. However, so far no one has been able to come up with a better way. I think gelatin testing has advanced bullet design for the better. Remember the gun magazines in the 70s and 80s that would show huge holes made by lightweight bullets shot through clay. The ole' 45 ACP would have a hole in the clay a little bit larger than the bullet and next to it would be some hot shot 32 ACP ultra velocity superlight bullet with a hole in the clay you could put your fist through. I think gelatin testing has overall been a positive addition to our science but gelatin testing does have some major problems as given by your report.

 

[mete]

None of the tests or formulas has ever meant to be an absolute - only a guide !! And when it comes to the "one shot stop" forget it just shoot and continue to shoot until the BG is no longer a threat.

 

[rockstar.esq]

The calibration question led me to think a little. The "standard" bad guy may be a little more difficult to establish given that we aren't made of gellatin ( well maybe a few of us). I think additionally there is little arguement that a 7mm mag will kill a deer however the same load on a chipmunk leaves a fine red mist. The size of your target is really more of a variable that what we might like to believe. I have read Massad Ayoob's reports and sometimes he advocates shooting for the center of mass other times he advocates shooting for the pelvis. Every time I hear a "statistic" I have to wonder about the variables. A lot of people feel "under bored" with anything less than a .45, good for them. Most of the worlds militaries use a 9mm of some kind, they kill lots of people every year. None of this makes one better for all things. I agree with METE, shoot accurately, and continue to shoot. Really it's the best you can do.

 

[Sam]

If the statistical data was properly done with all of your questions answered and corrected, gelatin shooting is only a valid comparison against identical blocks of gelatin with bullets fired from the same gun etc.etc......

Having never hunted gelatin or been attacked by a block of gelatin, I quit paying attention to them at all.

Sam

 

[Zak Smith]

With regard to poor calibration, it is a failing of the experimenter, not necessarily the method. Such a failure to document would invalidate the data in those improper experiments, not invalidate the method as a whole.

 

[coylh]

To balance out my critisims, let me also point out what I think
could be done to improve comparisons. Just to be clear, I don't
think gelatin testing is worthless, quite the contrary. But, out
of the several hundred gelatin test results that I collected, I
found that only a handful were actually useable for comparing two
cartridges or bullets. So, while gelatin testing in theory is great,
gelatin testing as it is available to a casual web surfer is poor.


------------

Well documented shoots! All gelatin shoots should be documented as well as
http://www.firearmstactical.com/test_data/45acp/rem45-185gs+p-g30.htm

Useful information:

1. The date and temperature
2. The gun model and barrel length used
3. The particular load, bullet weight, product and lot numbers
4. The BB calibration data for each block of gelatin (velocity and penetration)
5. For each shot the velocity, penetration, and final diameter
6. If averaged values are listed, a standard deviation should also be given
7. For each penetration value, a calibration corrected penetration value
8. The dimensions of each gelatin block used.
9. The distance between the gun and gelatin.
10. If any intervening barriers are used (cloth, glass, etc) a full description of them
11. Any other useful information, such as the weight of the recovered bullet,
depth of significant fragments, jacket seperation, orientation of the bullet in
its final position, etc.
12. Pictures! A picture of the recovered bullet is worth a thousand words.
13. The percentage of gelatin used.

All of these are simple and cheap to record!


------------

Consistent use of barriers. The FBI has a fairly comprehensive test protocol
for barrier-before-gelatin penetration. Unless you have a really good reason,
like you're testing for a specific building, it's better to follow their lead.


------------

I haven't been able to come up with a good and simple way to measure bullet
face surface area. Essentially it's not important to me, because I'd rather
measure the actual hole made, rather than measure the bullet and estimate the
hole. Bullets sometimes go sideways and backwards through a target which
confuses the issue anyways.

So, pick a standard method and stick with it. The FBI's average of smallest and greatest
diameter seems good enough.


------------

Inconsistent penetration would probably not be an issue if the gelatin were
properly calibrated and documented. At least then, the inconsistency could
be blamed on the bullet's performance rather than the gelatin itself. When
5 shot averages are made, include the standard deviation so we can see if
wide swings are normal for that bullet type.


------------

Theoretical Hole Volume. Someone clever needs to figure out a way of measuring
the permenent cavity volume in a block of gelatin so we can actually know
how much tissue would be destroyed. Sometimes I see dye in the hole to make the
cavities more visible, so it appears that you can put a liquid inside. If
that doesn't work, how about filling the hole with something solid such as
airsoft pellets: "This bullet made a 247 pellet hole."

 

[roo_ster]

Well-Founded Doubts

Even if you make the assumption that all the gelatin tests were performed identically AND had identical results, you are left with the limitations & assumptions of the gelatin method, its particular wound model, and its measures of effectiveness.

Any model is just that...a model of reality. One hopes that the model has some predictive power in the real world, but this is not always the case. The best test of a model is how it comports with data collected from reality.

"Reality" in this particular case is a bit slippery, as shootings of humans are not held under controlled conditions.

[I seem to recall a group of folks who collected actual shooting data. I can not recall their names, but I am given the impression that they have been discredited. I do not know if this is because of sloppy methodology, politics (losing out vs the gelatin supporters), or what. It would be nice to be able to give the gelatin regimen a reality check.]

Whatever model used, it must be used with an eye on its limitations and an understanding that the results are to be tempered with the experience of those closest to the subject at hand.

Beware the model evangelist who does not openly convey his model's assumptions & limitations.

 

[Zak Smith]

I think limiting one's research to what he can find online in deciding what gel results are worth is a mistake. People actually study this stuff professionally and publish in journals about it. For example, I know there is a method to quantify temporary cavity from static gel results, but I've never seen it mentioned on an online source. Consulting the papers and some experts in the field would probably help a lot in determing for one's self what gel can actually do.

-z

 

[sm]

None of the tests or formulas has ever meant to be an absolute - only a guide !! And when it comes to the "one shot stop" forget it just shoot and continue to shoot until the BG is no longer a threat.

Agreed.

Granted some great points have been made in previous posts. I respect the efforts and the finiding of those more learned than I.

I am fortunate to have spent a lot of time with shotguns and patterning pellet loads and groups for slugs since I was a wee brat. This transitioned into bullets and such.

I learned - Shot placement is the key. In order to have shot placement, the ammo must feed / extract , not only the gun , but the magazines as well, then POA/ POI.

Makes no nevermind what a shotgun bbl or choke is marked - what does the pattern board say MY gun does. Because I have taken the same make, model choke and ammo - and rec'd differing results, from 3, 4, 5 and 6 shotguns just alike , same fixed choke or screw in choke.

Done the same thing with the same 3 handguns for instance, some guns don't like a certain ammo.

So for me, I shoot pattern boards, and I shoot Dirt. In comparing what the bullets, pellets, slugs do in critters, to shooting Dirt, I have for my needs some really great comparisons to go on. Right scary as to how close some perform for ME.

200 rds fired from guns and mags before I carry it for serious stuff.

Some ammo is hard to find, expensive, or if really new, they may change the thing.

So for ME what I read about is just part of what I learn from and use. Because in a serious situation is NOT the time to find out that what worked for Someone else, in a gun like mine that won't feed, extract or heads off into the next county instead of POA / POI ...well dead is forever.

 

[MikeJ]

I don't know how many people would agree on this point but it does seem to me that the bottomline goal of any bullet testing, theory, statistics etc. is to predict as accurately as possible the effectiveness of one round vs. another. With that goal in mind and knowing that shooting into an inaminate object is not the same as shooting a living being with varying degrees of motivation, resiliency, temperment etc. boils down to how does the bullet perform. Having been, many many years ago, a disciple of Marshall and Sanow and now realizing the inherent flaws in that theory I believe that a study based soley on how does the bullet perform in real world situations would be of greater value than any theory on how it performs in gelatin or did it stop the perp in his tracks. In other words, did the bullet expand as advertised and did it penetrate as described. If the bullet does these things the rest is strictly conjecture as two identical rounds that perform identically may have two very different results. One person might be immobilized immediately due to shock etc. while the other person continues the fight with apparent immunity to the wound they have received. I guess you might say that I don't have a lot of faith in gelatin testing or one shot stop theories. What I would like to see are consistency statistics as to how the bullet performed in real life scenarios.

 

[mainmech48]

I've gotta agree with Clint Smith on this'un; don't ever recall being attacked by gelatin nor reading about anyone who has.

Shooting gelatin gives you valid information on the effects of bullets on gelatin. Infer what you wish. How it actually works on animals, two or four-legged, can only be determined in the field.

Comparing apples with apple-like substances still tells you squat about the true nature of apples.

 

[Zak Smith]

The problem with shooting things "in the field" is that the "experiments" are neither controlled nor repeatable, both critical to the scientific method.

 

[Sean Smith]

Bottom line is, if you want to compare the terminal effects of different loads, you need to compare them in a uniform medium, otherwise you are going to get inconsistent results that have nothing to do with the load's inherent properties.

Without getting into theory, it is easy to prove the worthlessness of the M&S "one shot stop" figures. The OSS numbers for .308 rifles and 12ga shotgun slugs are almost identical to those for some .40 S&W pistol bullets, even though the former are, objectively, an order of magnitude more destructive than the latter. A study that can't reliably detect huge differences certainly can't detect small ones, and is thus a waste of everyone's time.

All gel testing does is give you a consistent (at least if you use properly calibrated gel) yardstick for comparing the relative tendencies of different loads to penetrate, expand, fragment, et cetera. If you want to know what load will, on average, penetrate more, gel testing will give you very worthwhile data. Because it is not a perfect human target simulator (hint: no such thing exists or is even practical) does not mean that it cannot give you useful data.

 

[MrAcheson]

The OSS numbers for .308 rifles and 12ga shotgun slugs are almost identical to those for some .40 S&W pistol bullets, even though the former are, objectively, an order of magnitude more destructive than the latter. A study that can't reliably detect huge differences certainly can't detect small ones, and is thus a waste of everyone's time.

I'm not a fan of M&S OSS numbers. It think their work has been successfully show to be statistically dubious. On the other hand your criticism is, with all due respect, a little off base. Once you have enough power/damage/whatever to incapacitate someone anything above that is literally overkill. Yes a more powerful round will do more damage, but you can still only kill someone once. So once you hit the physical threshold required to do that kind of damage, more is no longer better (or much better). You hit diminishing returns. This is not liability of the study. This is how real life works.

Gelatin testing has its flaws. It is best used for simple comparisons. If you look at one guy's testing of one round verses another, then chances are his tests will be of the same form and directly comparable. However when you look to take all gelatin testing performed by people as a whole, things do fall apart rather quickly because test procedure isn't completely standardized.

And, yes, should I ever be attacked by a Gelatinous Cube, it is a good thing I now know what gun to use.

 

[mainmech48]

The trouble with real life is that it's also neither controlled nor repeatable. This may not be compatable with the "scientific method", but it is what it is.

Deductive reasoning from questionable data is a highly organized way to determine a wrong answer with perfect confidence. All of the wishfull thinking you care to indulge in won't change that one whit. Just because a thing is logical doesn't make it either true or valid, and betting something so precious as life on theoretical assumptions derived from hypothetical situations is still a sucker's bet.

 

[Zak Smith]

The trouble with real life is that it's also neither controlled nor repeatable.

This really makes no valid point. If the choice is to either have some reliable data or no reliable data when entering a chaotic situation ("real life"), some reliable data is better than none.

The same could be said for external ballistics (trajectory). In real life, you'll have wind and varying conditions. You don't throw up your arms and give up, or use data gathered in some other set of random conditions. You use the ballistic model and it'll get closer than anything else.

Deductive reasoning from questionable data [...] and betting something so precious as life on theoretical assumptions derived from hypothetical situations is still a sucker's bet.

It behooves those in serious circumstances to use the best knowledge available.

-z

 

[Boats]

You're really nowhere until you have shot the requisite number of 160# French goats.

I look at handgun ballistics this way:

Has it stuck around in a police or military application as a frontline caliber since it was introduced? (No? Don't use it; Yes? Use it.)

Is the caliber put to use in a platform I like? (No? Don't use it; Yes? Use it.)

So, .380 and .38 Special have become BUG calibers, I don't use them for SD. I use 9mm, .357 Magnum and .45ACP. The FMJ or LSWC kept them on the street and battlefield, and the JHP loadings can only help against personnel. I like the 10mm on paper, but not the Glocks or Witnesses which are the only easy to find platforms for it.

Shoot jello or animals or track criminal slayings all you want, but if something qualitatively better were out there in handguns, it would be in use almost immediately.

What we see instead are folks trying to build the (much hyped) better mousetrap without proof it works better on the mice.

 

[happy old sailor]

do your own testing. there are many mediums available. it is not precise, or scientific, but it is great fun and very interesting. my fav has to be milk jugs of water, inline. you will have to drink a lot of milk to be able to do this, or have severasl ppl saving for you. the fun factor, for me, gets a near top rating for things to do with my handguns.

 

[Feanaro]

Comparing apples with apple-like substances still tells you squat about the true nature of apples.

If someone goes to a ballistic gel test for information on what a given load will do to a human(or an apple), they have a problem. It doesn't duplicate what happens when you shoot a person or animal. It gives you a method of measuring the differences between loads, beyond the usual velocity, grains, and such. It tells you how a JHP tends expand and how deep it tends to penetrate. Not how it will expand/penetrate in flesh, mind you. But a bullet that expands more than the rest in gel will likely do the same in flesh, the same for penetration.

As Sean Smith said; some info is usually better than none. I know that this load penetrates deeply in gel but still expands. It might not work that way on people but so far my only other choice is to close my eyes and pick one at random.

 

[BluesBear]

I agree that shooting Jell-Oâ„¢ isn't perfect. But it beats the heck out of Play-Dohâ„¢, The Yellow Pagesâ„¢, Ziplokâ„¢ sandwich bags full of sand or White Castleâ„¢ pickle buckets full of dihydrogen monoxide.

Ordinance gelatin is designed to simulate muscle tissue. It is used because it's the medium in which recovered bullets most closely match bullets recovered from living human tissue. Of course it's not perfect.
For example 12" of penetration in Jell-Oâ„¢ doesn't mean it will penetrate 12" in a human. If that were so then 90% of all human wounds would be in and out.
No matter how many pairs of Wranglersâ„¢ you dress it up in there are still no bones, organs, fatty layers or a circulatory system.

IF someone could develop a medium that EXACTLY mimics the human body the ballistic would would beat a path to your door.

But right now it's the best we have.

 

[Sean Smith]

Once you have enough power/damage/whatever to incapacitate someone anything above that is literally overkill.

Your comment would make sense if handguns were as powerful as shotguns and shotguns were as powerful as grenade launchers. You really seem to have an inflated idea of how effective handgun cartridges are. Any index that puts handgun "effectiveness" against anything bigger than a woodchuck at 90%+ is on the face of it absurd.

 

[only1asterisk]

Ha-ha! Bear said dihydrogen monoxide!

David

 

[roo_ster]

My empirical side likes the idea of testing bullets in a uniform medium. It's controlable & repeatable and you get the "best" data. Hooray for empiricism.

But, once I start thinking too much about shooting gelatin I am reminded of the drunk who looks for his keys under the street lamp...because that is where the best light is. The methodology of using light to aid in finding the keys is defensible...and will condemn the drunk to never solving his problem.

I find it difficult to believe that no one has been able to get good data from the field. Police reports, autopsy reports, etc. for those who want to dig into the past. A detailed questionnaire to fill out for homicide by firearm for the future.

Yes, there are a lot of variables. A lot of those variables are already recorded (firearm, cartridge, distance from shooter to target, entry angle relative to top dead center, which organs were pierced, was the target on stimulants, etc.) and a few others can be reasonably determined (was the target agitated/unsuspecting, etc.). We have enough homicides so that over a couple years we could control for such things.

 

[Zak Smith]

I had the chance to talk with a nationally known ballistics expert today.

Below are quotes taken from this thread. All convey the idea: that gel testing has no relation to actual terminal ballistics and it can only be used to compare loads against each other as they perform in gel.

None of the tests or formulas has ever meant to be an absolute - only a guide !!

The "standard" bad guy may be a little more difficult to establish given that we aren't made of gellatin ( well maybe a few of us).

If the statistical data was properly done with all of your questions answered and corrected, gelatin shooting is only a valid comparison against identical blocks of gelatin with bullets fired from the same gun etc.etc...

Any model is just that...a model of reality. One hopes that the model has some predictive power in the real world, but this is not always the case. "Reality" in this particular case is a bit slippery, as shootings of humans are not held under controlled conditions.

I don't know how many people would agree on this point but it does seem to me that the bottomline goal of any bullet testing, theory, statistics etc. is to predict as accurately as possible the effectiveness of one round vs. another.

In other words, did the bullet expand as advertised and did it penetrate as described. If the bullet does these things the rest is strictly conjecture as two identical rounds that perform identically may have two very different results.

Shooting gelatin gives you valid information on the effects of bullets on gelatin. Infer what you wish. How it actually works on animals, two or four-legged, can only be determined in the field.

All gel testing does is give you a consistent (at least if you use properly calibrated gel) yardstick for comparing the relative tendencies of different loads to penetrate, expand, fragment, et cetera. If you want to know what load will, on average, penetrate more, gel testing will give you very worthwhile data.

Gelatin testing has its flaws. It is best used for simple comparisons. If you look at one guy's testing of one round verses another, then chances are his tests will be of the same form and directly comparable. However when you look to take all gelatin testing performed by people as a whole, things do fall apart rather quickly because test procedure isn't completely standardized.

If someone goes to a ballistic gel test for information on what a given load will do to a human(or an apple), they have a problem. It doesn't duplicate what happens when you shoot a person or animal. It gives you a method of measuring the differences between loads, beyond the usual velocity, grains, and such. It tells you how a JHP tends expand and how deep it tends to penetrate. Not how it will expand/penetrate in flesh, mind you. But a bullet that expands more than the rest in gel will likely do the same in flesh, the same for penetration.

It turns out, that idea is just wrong, totally wrong.

jfruser was closest when he said:

I find it difficult to believe that no one has been able to get good data from the field. Police reports, autopsy reports, etc. for those who want to dig into the past. A detailed questionnaire to fill out for homicide by firearm for the future.

It turns out that the question "Are ballistic gel predictions confirmed in real shootings?" has been asked and answered.

Shame on you guys in this thread for not doing your homework!

Several police departments have done studies which compared the actual damage caused by gunshot wounds of the departments' loads to the predicted gel results. With an understanding of physiological structures which affect penetration the actual shooting results averages match the gel results in both expnasion and penetration.

Two such departmental studies include the San Diego PD which looked at 150 shootings, and the CHP which looked at 65 shootings. Furthermore, one can read what Eugene Wolberg has written about the subject.

For example, http://www.firearmstactical.com/afte.htm

Mr. Wolberg’s study proves that the average penetration of bullets in the human torso is nearly the same as that in properly prepared and calibrated 10 percent ordnance gelatin. This analysis refutes another of Marshall’s and Sanow’s unsubstantiated claims which they make on page 171 of their text: "Penetration distances in 10 percent gelatin consistently will be 15 to 20 percent shallower, on average, compared to penetration in a living human being." Documented scientific research has proven that properly prepared 10 percent ordnance gelatin not only duplicates the bullet deformation and fragmentation seen in living tissue, but that the penetration results in 10 percent gelatin are within 3 percent of those measured in living tissue.15

(15 refers to # Fackler ML , Malinowski JA: "The Wound Profile: A Visual Method for Quantifying Gunshot Wound Components." JTrauma, 25(6): 522-529; 1985)