It seems to me I read an article a while back that suggested up to 60% of gut shot deer lived (shot with an arrow). It said something about deer intestines being able to seal back up after being punctured. They claimed this was because the intestines are often punctured by sticks and vegetation that the deer eat. I might have got it wrong since it has been a while since I read it, I don't even remember what magazine it was in. Maybe someone else remembers seeing this article?