Losing faith in gel tests

[ugaarguy]

Fellow High Roaders,

Some things I've indirectly observed of late have caused me to seriously question ballistic gellatin testing. In the recent "Falling Bullets" episode of the show Myth Busters they are trying to determine how high both a 9mm bullet and also a 30-06 bullet go in the air when fired strait up. Their first attempt was to use how deep said FMJ Bullets went into 10% ballistic gel (90% water) then compare the density of the gel to the density of air and extrapolate the result. Now the falling bullets thing isn't what I'm concerned about. What I'm concerned about is how that 30-06 FMJ round acted in the gel - it disintegrated within six inches. The Myth Busters reasoned that this happened because the gel is 90% water and they got similar results when shooting a variety of high velocity FMJ rounds into water (including 30-06 FMJ) when looking at the shooting into water myth. Now we know from evidence - wars - that FMJ rounds at high velocity tend to either go thru, or tumble within, when shot into a person. They don't disintegrate like in the water and, more notably, 10% ballistic gel tests. So we now have pretty good evidence that ballistic gel isn't an accurate gauge of how a bullet will perform on a person being shot in self defense/ an animal being shot when hunting. Then today I read this post; http://www.thehighroad.org/showpost.php?p=2411677&postcount=20, by cookekdjr. Now we have another piece of evidence, presented by David, that bullet performance in a human is not the same as in ballistic gel. So, other than conducting a new version of the rumored Strausburg Goat Tests, what do we do? Do we shoot bullets into sluaghtered animal carcasses and compare the resultant wound channels? What does bullet performance in ballistic gel really tell us?

 

[RyanM]

Wrong, wrong, wrong, and wrong.

http://www.firearmstactical.com/images/Wound Profiles/M193.jpg
http://www.firearmstactical.com/images/Wound Profiles/M855.jpg

Fragmentation ("disintigration") of M-16 FMJ ammo is extremely well known.

http://www.fen-net.de/norbert.arnoldi/army/wound.html

East German 7.62x51mm (.308 Win) ammo has been observed doing exactly the same thing, in people and in gelatin.

Previous generation hollowpoints like Silvertips and Hydra-Shoks will not expand in clothed gelatin either. Clothing plugs them up and prevents expansion. Modern hollowpoints don't have this problem, and perform almost identically in human tissue and in gelatin.

http://www.btammolabs.com/fackler/winchester_9mm.pdf
These bullets all expanded in humans, and penetrated very close to what they do in gelatin.

 

[Correia]

The actual use of ballistic gel is a little more complicated than what the Mythbusters do also. If I recall correctly, it also needs to be refridgerated to a certain temperature, which makes it harder.

 

[Brother in Arms]

I dont believe in the ballistic gelatin either as its not a human being. Simply put it wont react the same.

Also the older m16 round had a thin jacket and a lead core which helped cause the fragmentation of the jacket separating from the lead. The newer ammunition doesn't do this.

Brother in Arms

 

[dgrolem]

I think this is a serious and important question.

For example, I have talked to several LEOs who have had long careers in high-crime areas. One visited every autopsy of every department shooting over a 20+ year career. His comment was that almost none of the many dozens of hollow points he saw extracted ever expanded unless they hit bone. Most, he claimed, "...looked brand new" with the exception of rifling marks. Yet, ballistics tests in gel show HP expansion nearly every time -- or at least it is implied that they expand every time.

This, and other conversations, leads me to think that gel is not a good surrogate. It is certainly convenient and leads to a large amount of data, but echoing UGAARGUY, is it any good?

 

[ugaarguy]

Ryan M,

The Third link you cite shows the 7.62 nato round with 58 cm, or 22" of penetration. The shot into the ballistic gel on myth busters achieved almost total fragmentation within 6 inches. The information linked also cites partial fragmentation and more of a tumble. I think I clearly noted that tumbling is normal in my post.


Further, we now another indirect observer, dgrolem, who has heard of similar handgun round results in humans as seen at autopsy by a LEO. Flat out we're getting reports that self defense JHPs are not performing in gelatin like they are in humans. With these reports of lack of expansion we're getting reason to argue toward the 357 Mag, 40 S&W, 45 ACP arguement. 357 Mag to get enough velocity to fragment the smaller bullets; 40 S&W since it has enough velocity to get good penetration and a larger starting bullet diameter; 45 ACP since its amongst the largest diameter rounds that can be practically carried even though it has lower velocity than the first two.

 

[RyanM]

For example, I have talked to several LEOs who have had long careers in high-crime areas. One visited every autopsy of every department shooting over a 20+ year career. His comment was that almost none of the many dozens of hollow points he saw extracted ever expanded unless they hit bone. Most, he claimed, "...looked brand new" with the exception of rifling marks. Yet, ballistics tests in gel show HP expansion nearly every time -- or at least it is implied that they expand every time.

I already said, clothing. Test a Hydra-Shok against gelatin with clothing on it, and maybe some thin leather to simulate skin, and it won't expand. Only the very recent hollowpoints made within the last decade or so will expand reliably through clothing.

 

[ugaarguy]

Ryan M,

I understand on the clothing point clogging the hollow points.

All,
I'm just trying to bring up that there are many variable and ballisti gel, clothed or not, may not be the best performance indicator. However, its the easiest to use medium we have for comparison right now. I also need to make this very clear; although the observations at autopsy showed that the bullets didn't perform in people as they did in gel, these were still observations at autopsy - the people weren't any less dead.

 

[MICHAEL T]

Gelatin not working how about. Bullet catcher wanted. Another job Americans won't do. Sounds like more work for.

 

[RyanM]

Check the 4th link. It's a big file, but it does show that modern hollowpoints perform about the same in gelatin as they do in people. That's all autopsy data, from people who were shot and killed by the San Diego PD. Of all 28 shots in the study, none failed to expand. Because they're a modern hollowpoint designed to function through clothing. That study also found that the average penetration was about the same, though with a wider spread in human tissue.

The reason why 99% of hollowpoints don't expand is because 99% of the hollowpoints people are hit with are either low quality or poorly designed. Most shootings are perpetrated by criminals, and criminals get whatever's cheapest. Even private citizens rarely know better. Do a quick poll of what ammo people here carry, and most likely almost half will say Hydra-Shoks. Those people won't have expanding ammo if they ever have to shoot someone, because Hydra-Shoks are not designed to expand through clothing. They were designed more for hard barriers like wood and metal. Soft barriers plug them up.

The reason for the "differences" between gelatin data and real shootings are clothing. That's the only reason. http://www.firearmstactical.com/briefs.htm Look at the test data there, and you'll see that all of the previous generation hollowpoints tested, except one, failed to expand through the heavy clothing test (18+" penetration bullet not recovered indicates that the bullet didn't expand and just penetrated like an FMJ). 4 layers of denim is not meant to simulate any one particular garment, it's merely a test of the bullet's engineering. Studies have shown that bullets which expand in gelatin through 4 layers of denim will expand in the street. Like the Winchester 147 gr subsonic JHP.

Actually, given that torso shots and 4 layer denim shots both usually result in less expanded diameter than water or bare gelatin shots, 4-layer denim gelatin is probably a much more accurate indicator of a bullet's real performance, than bare gelatin is.

 

[Shawn Dodson]

Suggest you see: "US Military Joint Service Wound Ballistics Integrated Project Team" at http://www.firearmstactical.com/tacticalbriefs/2006/04/main.htm

Also: http://www.firearmstactical.com/tacticalbriefs/2006/04/02/0604-02a.htm

Although the topic of the article is mostly unrelated, it does present information that addresses your concerns about the validity of ordnance gelatin as a realistic soft tissue simulant (scroll to almost the bottom of the page to the "extracts" sections): http://www.firearmstactical.com/tacticalbriefs/2006/04/03/0604-03a.htm

 

[ugaarguy]

Faith Restored

Guys, Thanks for the links to the research. Excellent info on the comparison of new generation hollow points to older ones and the SDPD shooting autopsy comparison info. Admittedly I could have searched the web and tried to find it myself, but then we wouldn't have this cool thread .

 

[isa268]

funny you say this now.

Double Tap Ammo http://www.doubletapammo.com/php/catalog/index.php just did a test on his ammo using 10% gel and 4 layers of denim

it can be found here.

http://glocktalk.com/showthread.php?threadid=336612

 

[dgrolem]

As I understand it, the autopsy reports I mentioned were all on the BGs. A few years back, the department switched from JHP to FMJ as a result, though it is left to the individual officer to decide. The two supervisors that I spoke to think that JHP are a waste of $$. The more senior LEO has personally put 10+ folks down (some dead, others not).

While a couple of LEOs does not make a credible study, it does point out a possible problem between gel results and live fire.

 

[CWL]

Ahem y'all,

Ballistic gelatin is used because it is consistant. Unlike variables of different body shapes + muschle + bones + bodypart(s) hit, gelatin replicates the average of bullet path & performance in the human body.

Really useful stuff for averaging bullet penetration & destruction of tissues, but not meant as guarantee of individual bullet performance inside real human. Too many variables between individuals & bodyshapes & location of entry & angle.

Gelatin = way to test consistency of performance of bullet.
Gelatin = averaged human tissue (combining muscle, organs, fat, bones).

 

[RecoilRob]

The most interesting thing to me (re:unexpanded bullets recovered during autopsy) is that they were RECOVERED. Meaning, they didn't expand yet they didn't Overpenetrate as so many worry about.

Seems the 'need' to use HP's to avoid the dreaded Overpenetration is mostly a Red Herring.

 

[Beachmaster]

Don't worry about the gel. I have never seen a person attacked by balistic gel (OK once, but that was on Jerry Springer, so I don't believe it!) Worry about hitting the target, and you will be happy with the results of most modern ammo!

 

[Shawn Dodson]

I have never seen a person attacked by balistic gel...

What's your point?

 

[The Real Hawkeye]

The should shoot goats and pigs to see what these rounds will do in a person. Make sure to clothe them like people too.

 

[Shawn Dodson]

Cookekdjr wrote <I spent years looking at autopsies as a part of my job. The most common calibers (in no particular order) were 9mm, .40, .45, and .357, although I have also seen 12 gauge, 30-30, .25acp , 22lr, .380 etc.
I was reading the famous/infamous FBI report from 1989 that led to the 10mm/.40 S&W development, when I realized I was never seeing expanded hp's in handgun fatalities. I asked one of our ME's (the dr's who perform the autopsies) and she said she rarely sees expanded hp handgun bullets. Keep in mind she sees gunshot wounds almost every day. I asked some of the other ME's, and they all gave the report: they rarely or never saw expanded handgun hp's. Sometimes you see jacket separation, but rarely expansion. Classic mushrooms? Never.
Anyway, I've posted about this before, sometimes to much derision. Whatever. This is what I saw over hundreds of cases, and I asked the ME's about their experiences from thousands of others, and it matched mine. YMMV.
-David>

Blah, blah, blah.... Anecdotal report not substantiated by forensic evidence.

 

[psychophipps]

And we also know that your typical BG and LE personnel blow the big bucks on the latest high-speed, low-drag bullets regardless of the cost. What do you mean they don't?

Mark(psycho)Phipps( HAHAHA! )

 

[pauli]

Anecdotal report not substantiated by forensic evidence.

you say that as though this thread didn't begin with someone watching mythbusters.

 

[antsi]

----------quote----------
While a couple of LEOs does not make a credible study, it does point out a possible problem between gel results and live fire.
-------------------------

CWL had it right.

There is definitely a use and a place for laboratory testing. This allows comparisons between different bullet designs "under controlled conditions." If you are doing product testing and development, you have to be able to reproduce the same conditions to make valid comparisons, otherwise you can't test and develop.

In real shootings, there are many more variables involved and nobody can predict exactly what is going to happen. Lab testers have tried to incorporate some of these variables, like shooting at gel through car doors, drywall, etc. Using gel with denim over it to simulate clothing is another example. However, until someone figures out how to simulate gel on crack, gel on meth, gel pumped up on adrenaline from having domestic dispute with its gelfriend, gel running at you with a baseball bat, etc, there are still going to be things that happen in real life that don't happen in the lab.

That doesn't mean there's no use for lab testing. It just means you have to be cautious about making predictions of real world events based on what happens in a lab.

One other thing - I would be leery of looking at autopsy results "over a 20 year career" because bullet designs have changed a great deal in the past few years. The older type JHP's often did fail to expand in real life - and lab testing with clothed gel has reproduced this kind of failure. The newer designs - developed and tested using clothed gel - are meant to expand more reliably under more different kinds of conditions. Of course that doesn't mean they are always going to, but I'd sure have more confidence versus the 70's and 80's JHP's.

 

[Shawn Dodson]

Using gel with denim over it to simulate clothing is another example.

Incorrect. See: http://www.firearmstactical.com/tacticalbriefs/2006/04/02/0604-02a.htm

However, until someone figures out how to simulate gel on crack, gel on meth, gel pumped up on adrenaline from having domestic dispute with its gelfriend, gel running at you with a baseball bat, etc, there are still going to be things that happen in real life that don't happen in the lab.

Gelatin testing provides data on bullet terminal mechanical performance in typical soft tissues ONLY (penetration, expansion, fragmentation and yaw). It CANNOT be used to predict "stopping power."

It just means you have to be cautious about making predictions of real world events based on what happens in a lab.

Gelatin tests provide a reasonable indication of how a bullet can be expected to perform in an actual shooting, which is why it's the industry standard realistic soft tissue simulant. A bullet recovered from a human body is more likely to resemble one fired into gelatin than not. When performance differs there's a good reason for it. When the exact conditions of an actual shooting are matched in tests (what the bullet encountered from the time it exited the muzzle until it came to rest), performance in ordnance gelatin has been found to match.

Suggest you study: http://www.firearmstactical.com/tacticalbriefs/2006/04/03/0604-03a.htm

 

[gezzer]

Mythbusters lost all credibility when they stated tracers are made from phosphorant paint on the tip that burns from air friction. Their FBI expert confirmed this.

I'll bet the FBI guy had a big laugh getting this on the air. Mythbusters lost all credibility when they stated tracers are made from phosphorant paint on the tip that burns from air friction. Their FBI expert confirmed this.

I'll bet the FBI guy had a big laugh getting this on the air.