The ball doesn't fragment either.
My experience and therefore also my opinion is a pure lead roundball doesn't fragment but stays together. Somewhere, I have a .45 cal. roundball that hit solid spine bone and simply flattened. It is still close to 100% original weight. Range was about 50 yards. You woulda thunk that an oak tree fell on that deer the way he went down. But, not ded. Only deer I have had to give a cous 'd gras.