Seems if they are aware of you...otherwise spooked and adrenalin on overdose....they can take hits and punishment that makes you wonder how they are still on their feet. Times like that a large bull can be like shooting at a truck tire.
Caught unaware,with a bullet in the right spot, they aren't hard to kill. But sometimes they show little reaction to the shot;and as others have pointed out,their reactions to being hit by a bullet can vary all over the place IME.
