the kid hit the bull's eye yesterday

horse

because most cows have a double skull and when the Indians had bows before guns to kill a bull cow you had to hit it is the eye and the new settlers brought gun so there was no need to hit them in the eye any longer but for target shooting they seen the skill to hit it so the called the middle and smallest target a bulls eye

hit him in his eye with a gun or shadow's homing attack

There is no information to suggest either answer.