Texas10mm writes:
It's not living tissue and people aren't made of gel.
Properly prepared and calibrated Type 250A ordnance gelatin depicts a reasonable representation of soft tissue wounding effects and bullet terminal performance as verified and validated by comparison with actual shootings. For an example, I refer you to pages 12-19 of the following link -
http://thinlineweapons.com/IWBA/1994-Vol1No4.pdf
Gel doesn't replicate living tissue. The skin layer can equal 2-4" of gel penetration. Your skin isn't 2-4" thick.
Skin can present as much as 4" of penetration resistance (skin of the back) when a bullet EXITS. Unshored skin stretches. Shored skin (entry wound) is simply crushed by the penetrating bullet and presents no additional resistance.
Calibrated gel allows us to test bullet performance. It in NO way simulates what happens when a bullet hits living tissue.
Your belief is untrue. Please provide a source for your misinformation. There's a reason why properly prepared and calibrated Type 250A ordnance gelatin is the gold standard soft tissue simulant. It has been verified and validated by comparison with actual shootings. See pages 42-43 of this link -
http://thinlineweapons.com/IWBA/1996-Vol2No3.pdf
Why does the FBI want 18" of penetration? Most people aren't near that thick on a full frontal shot.
It's because if you have to shoot through say an arm you will still need the penetration to enter the body cavity.
An arm can easily equal 12" of gel penetration. Two layers of skin, muscle, maybe a bit of bone. Then another layer of skin hitting the body. You've already used up 6-12" of gel penetration just going through skin.
Why does the FBI want up to 18" of penetration? You are correct that a bullet that has to negotiate an outstretched arm holding a weapon will encounter several inches of muscle tissue. In the FBI-Miami shootout one bullet that was headed toward Platt's heart entered his upper arm just above the elbow crease. It transited through the biceps muscle and exited the arm in the armpit area then penetrated the thoracic cavity. The Winchester 115gr Silvertip JHP bullet performed as designed and as a result its effective penetration depth was approximately 10". It stopped about an inch short of the heart.
Note that the FBI is more concerned about a bullet reliably achieving a minimum penetration depth of 12-inches based on informed medical opinion.
Well-designed expanding handgun bullets, in common combat handgun calibers, penetrate about 14-16 inches. The physics of handgun bullet velocity, weight, post-expansion sectional density, and tissue resistance to bullet penetration constrains expanding bullet penetration depth to the 14-16 inch range. This is the range of penetration achieved when a bullet is designed to reliably expand and penetrate a minimum of 12-inches.
I'll stand by my statement. Gel is nothing more standardized test medium, and like any standardized test medium the results can be gamed.
Properly prepared and calibrated Type 250A ordnance gelatin accurately replicates the inertial and shear forces of human soft tissues. Calibration ensures it cannot be "gamed". See pages 21-23 of this link -
http://thinlineweapons.com/IWBA/1997-Vol3No1.pdf