Explanation of Penetration's Importance

[Duckford]

Reading various forums, including this one, and all the talk about blocks of gel and the necessity of deep enough penetration to vitals being the most important factor in bullet and load selection, and various Youtube videos from various gun channels and pundits, I've heard everything on the subject. All the way from "them ur just blocks o Jello, means nothing" to even hearing someone quote Ayoob as saying that 12-18 inches is outside the normal dimensions of a human being. (If the respected Mr. Ayoob didn't say this, or did, I'm not sure, I do not like false attributions if he did not), and all the talk that getting to vitals is actually not that hard considering that the average chest is not that deep.

I enlisted a friend this weekend and took 45 minutes out of a Saturday to create a video that refutes the notion that the dimensions of a man, in the conditions of combat, and the angles of the real world fight, would not seem to need 12-18 inches of legitimate penetration. Beyond the differences between human flesh and gel, 12 inches can certainly be a short way in real life.

[ame]https://www.youtube.com/watch?v=JQcNjIThmHQ[/ame]

Perhaps a bit winded, like I am in many of my posts, and perhaps a bit simplistic for those more familiar, and not well scripted, nor with enough time taken to get the most scientific of measurements down to the half inch or less. However, it should demonstrate the concept that attackers will not always come at you flat chested, square on, and give you the type of shooting angle that you get on your silhouettes at the range.

 

[alwslate]

You are absolutely right. And those of us who are hunters and have
shot a fair number of large animals know that too much penetration is
better than too little. Shot placement is number one and penetration
is number two and everything else is of relatively minor importance.

 

[DWalt]

The FBI adopted the minimum bullet penetration in ballistic gelatin standard. See this site about the FBI penetration tests: CALIBERS -- FBI Ballistic Test Protocol I have a great deal of data regarding FBI test results involving testing of a very wide range of calibers and bullet types (handgun, rifle, and shotgun). I don't know if that information is widely available, but I got it directly from the FBI about 10 or so years ago when I was working on a small arms ammunition development project for the USAF.

 

[Whitwabit]

DWalt has provided the FBI Standard which I have read other places also ..

The ballistic gelatin is suppose to replicate the human body and is NOT 1inch in the ballistic gelatin for 1 inch in the human body .

12 -18 inches in ballistic gelatin represents the depth need to hit the vital organs in a human body .. that is per the FBI standards ..

On YouTube The Ammo Quest Channel has produced some of the Ballistic Gelatin Test for different calibers per the FBI standard test with 4 layers of denim .. and is close to what the FBI would find if doing the test ....

The test you did measuring the human body mean nothing ..

 

[Duckford]

I stated there was differences between human tissues and ballistics gel, I never stated once that it was an equivalent, and stated the video was for the concept of shot angle as a critical part of penetration to vitals in relation to ballistics gel and real life scenarios. Many on the internet have refuted the 12-18 inch criteria based on the idea that the human chest is far less than 12-18 inches. This video, as stated within the video, is only about a single concept, that absolute depth of penetration to vitals and how it factors into ballistics gel testing. Angles and depth of shot are important factors in the 12-18 inch computations, and this was simply made to show the effects and real depths possible due to angles, in order to enlighten those who think all shots are straight angles through the front of the chest wall.

So, Mr. Whitwabit, did my video fail to show the effect of angles increasing the depth of penetration necessary to reach vitals? In which way did it fail, and mean nothing?

 

[CB3]

Gel provides a consistent, measurable medium for testing different bullets at different velocities through no and common barriers. The tests must be scientifically reproducible to eliminate variables. The test medium and conditions have some relationship to human tissue, but that is not the point. Reproducible, scientific testing is. The FBI 12-18" is a minimum. Lung tissue has less resistance than 10" of belly fat and 1" of muscle. You can't have one realistic test that covers all conditions from all angles. So, the FBI came up with their tests as a mean average of expected bullet performance, and generally it works. Bullet and ammunition manufacturers have been building products to meet or exceed this testing. The actual results in humans do not directly compare to the gel tests--it's just approximation.

That being said, it is helpful to understand dimensions of humans to have some expectation of bullet performance. Intervening clothing, bones, bullet path (straight, ricochet off bone, poorly expanded uneven slug) all effect depth of penetration.

If your load does not reach 12+" after going through denim and gel, evidence indicates it will do less well against an actual attacker.

BTW, exit velocity of a defensive caliber expanded handgun bullet after passing through 12" of bare gel, if it does, is less than 300 fps and therefore unlikely to be lethal on a subsequent target.