Not sure where you are getting you information/"science" but according to Fackler:
"The test of the wound profiles’ validity is how accurately they portray the projectile-tissue interaction observed in shots that penetrate the human body. Since most shots in the human body traverse various tissues, we would expect the wound profiles to vary somewhat, depending on the tissues traversed. However, the only radical departure has been found to occur when the projectile strikes bone: this predictably deforms the bullet more than soft tissue, reducing its overall penetration depth, and sometimes altering the angle of the projectile’s course. Shots traversing only soft tissues in humans have shown damage patterns of remarkably close approximation to the wound profiles.
The bullet penetration depth comparison, as well as the similarity in bullet deformation and yaw patterns, between human soft tissue and 10% ordnance gelatin have proven to be consistent and reliable. Every time there appeared to be an inconsistency…a good reason was found and when the exact circumstances were matched, the results matched. The cases reported here comprise but a small fraction of the documented comparisons which have established 10% ordnance gelatin as a valid tissue simulant.
--“The Wound Profile & The Human Body: Damage Pattern Correlation.” (Martin L Fackler, MD, Wound Ballistics Review, 1(4): 1994; 12-19)