Bullets have more energy than arrows, and if fired from firearms adequate for the game being hunted, can smash even heavy bone and enter the vital organs. A spot in the center of the lungs or slightly lower should be a bowhunter's target every time.
Hunters using firearms have many more choices than bowhunters.
A bullet striking either the heart, shoulder, head, spine or lungs is fatal to big game animals due to the massive shock and tissue destruction involved. Once again, the chest area offers the best lethal target. The broadside shot is also the best single angle for accomplishing a double-lung hit, resulting in the collapse of both lungs. Find the best aiming point on a deer or other hooved big game by picking a spot halfway up the side of the animal and about a hand's width behind the hollow of the shoulder. Or, in your mind's eye, eliminate the head, neck and tail.