I would echo what the other guys have been saying- the most important factor in how quickly a game animal goes down is shot placement. The second most important factor is bullet performance. The third most important factor is the individual animal's reaction to the shot. Somewhere down the list is headstamp. Animals seem to DRT almost every darn time when you use a high-shoulder/spine shot, whether the bullet is .243", .257", 7mm, .308", .338", etc. An animal can run for a while without any oxygen. By taking out the lungs and heart, you're effectively cutting off the oxygen supply to the brain. After several seconds, the brain shuts off and the animal falls. If you take out the skeletal structure or the CNS, the deer has a much harder time running
A simple, yet effective equation that was concocted by John Barsness:
G + B + 2*L = DG
G = gun
B = bullet
L = lung
DG = dead game
It might take a few seconds and several yards before the animal falls, but when an expanding bullet goes through the lungs, it's game over. The more tissue you destroy, the better your chances are of finding the animal closer to the POI. Bullets like the Berger VLD or Hornady A-Max, etc, destroy more tissue in a shorter distance than a bullet like the Barnes TSX. One style has more violent expansion with limited penetration, and the other has limited expansion and deep penetration. The Nosler AB tends to be somewhere between the two.