Curious if there are any studies or data on how close 10% gel is to living flesh as far as penetration depth is concerned. The oft-heard comment with gel-testing of handgun rounds, is that "12-18 inches of penetration in gel doesn't equate to 12-18 inches in living flesh", but no definitive answer seems to be given of what it actually does equate to.

Obviously there will be huge variances in living animal penetration due to bone interference, fat/muscle ratio, etc; just curious about general correlations.

Man, there sure has been a lot of debate on this.  A number of members are pretty vehement on 10% ordinance gel calibrated properly and stored and used at the right temperature against all other gel products.  They point out that the use of this ordinance gel by the FBI comes from a lot of study by experts in the field, based on comparing forensically, human being wounds to various gel formulations.  Apparently, it's the best analog to human tissue.  But you're right that a human doesn't have a consistent tissue make up like a block of gelatin.  Organs, bones, fat, muscle, etc. all have different densities, but nevertheless, this 10% ordinance gel has been agreed upon as the best simulation media to test bullet terminal ballistics.  I have not found anything to argue this, and there are enough people whose opinions I respect that have endorsed the FBI test methods for me to dispute it.  If ammo tests are done using this FBI methodology and the calibrated 10% ordinance gel, I tend to trust the results more than methods that deviate from that.  Am I foolish?  Maybe, but I buy SD ammo that meets the FBI criteria and will not buy defensive ammo that doesn't.  I'm also careful to make sure the ammo I buy works reliably in my firearms and velocities and range are within the bullet's expansion or fragmentation thresholds.  Guys like Molon and bluefalcon on this board do a great service for us when report their testing experience.  It's been shown that data published by ammo manufacturers doesn't always hold up when tested.  Molon's data, for one, has been real helpful in this regard.

Honestly, I'm just being a careful consumer.  I make these purchase and usage judgements based on the research I do and the information available to me.  YMMV.

It is better for comparing rounds than determining absolute performance.

Agree; that's how I've understood it as well. Basically that it just gives a consistent media to get repeatable results for setting benchmarks. I've read articles and forum posts over the years commenting that handgun rounds almost always penetrate more in gel than in reality, and also ones that maintain that they almost always penetrate less in gel than in reality.

I've just never seen where anyone - on either side - actually backs up their premise with data of any kind.

You have been around since 2001, but never bothered to click on the FAQ at the top of the page?



Let me get you started:



http://www.ar15.com/ammo/project/Fackler_Articles/winchester_9mm.pdf

I've looked thru a lot of that stuff over the years, but obviously not everything. Thanks

This. It is a fairly controlled way to compare terminal ballistic performance. Actual performance in flesh is extremely variable depending on the individual's body, where it impacts, clothing, etc.

 

Consider calibrated 10% ballistic gelatin as a homogenized human. Like all simulants, it MUST be homogenous in order to be both useful and valid. Originally, it was only meant to simulate pig leg muscle in order to placate the animal rights activists in an era when we shot anesthetized live pigs, but it turns out to work well as a human tissue simulant.

Bullet penetration in actual humans is quite variable, sometimes to a striking degree, often without apparent reason. The newer designs are far more consistent than older designs, but there is still enough variability that arguing over whether HST is better than Gold Dot, etc. is like 2nd lieutenants arguing seniority.

I have had cases of multiple GSWs where FMJ under-penetrated JHP, and others where two identical bullets out of the same gun, passing on similar trajectories through the same body cavity of the same person, and striking essentially the same tissues throughout, have had wildly different penetrations (on the order of twice as much), despite looking pretty similar when I dug them out.

That caveat aside, gelatin IS very useful, for the primary reason already given above: it allows you to compare the likely performance of an unknown load with one whose performance is well-documented.

Where it is NOT terribly useful is in taking a gelatin-derived penetration depth and presuming equal penetration in a human body. We see those sorts of statements all the time justifying poorly-performing loads: "yes, the Tactical Buzzsaw Ninja load only got 6 inches of penetration in (uncalibrated) gelatin, but the heart is only a few inches deep in the chest; that's all the penetration you really need.", etc.

It's also not terribly useful if you only fire one shot of each load, but that's something for another argument.

It is just a real PITA to find uniform humans and then shoot them in the same place in a 'dynamic' situation.

A shot to the chest may hit a rib or slip between them.
You need the target to stop moving and be naked to (maybe) tell what the bullet will encounter.

And then their is that damn 'breast bone' that in younger humans is often still flexible cartilage more than bone.
It calcifies as we age (if nutrition is good).

Tell the target to eat better.

You could go for a lower shot ('gut shot').
But you better make sure there is not a lot of adipose tissue (AKA fat) on top of a uniform muscle wall.

And nake sure the clothing is nice and uniform.

Actual testing has shown 'clogging' of hollow points reducing their finction to about FMJ round nose.

Add to all that the shortage of volunteers for targets.