There really are ridiculous amounts of variables to deal with.
Shot placement is sometimes misunderstood.
How many times have we heard...
"I shot it right behind the shoulder, I KNOW I DID".
After tracking it for hours. You realize the shooter DID hit it
behind the shoulder. Its just that the deer was QUARTERING
TOWARDS him. Sooooo the deer was gut shot.
This would skew any test, even if sufficient caliber, and sufficient
bullet was used.
In other words on paper, the deer was "shot with .308 150gr bullet, right behind shoulder, and ran 300yds."


Tracking is really a misused term, with a proper shot. Following a blood trail, is....following!