It depends on where at the lung was shot. I had the story about a double lung that went for several hours. arrow was through both lungs, and staid in the deer. but it was shot towards the back of the lung and the wound was totally healed over. we went back in the next morning and had to put a kill shot in the deer. we found the arrow through both lungs. Amazing creatures. He was still alive, but you could tell he was very tired an just laid there to let us shoot him again.