That's it, it expends it's energy IN the target, the energy left when a rounds punches through the animal is wasted.
In Sixguns by Elmer Keith he spoke of growing up knowing Civil War veterans, one from each side, both in cavalry, who spoke of the 36 caliber round ball as the round "that would take the fight out of the man". As the union army NEVER had a contract for cartridges with a round ball, only conical, they must have cast their own or someway come up with them, perhaps loaded the first 6 with round ball and perhaps used the Gov. issued conical containing paper cartridges for reloads while fighting.
In my own experience a friend took up muzzle loader deer hunting, the first year he had a 45, his first deer was hit in the rib cage, nicked a rib, when to got to the other side it bounced back on the hide and rolled around inside, expending all it's energy, it dropped and stayed pretty much down as it died.
blessings