i second that, i was with a friend that arrowed a big black bear looked like a decent hit but we still waited, blood loked like a liver so we took our time, lots of blood the next day, we expected to find the bear. well we did but it wasnt dead and it did what black bears do best ran straight up the mountain and we didnt see another lick of blood, the bear bedded in a avalanch shoot that still had snow, i think the cold stoped the external bleeding. so my point they are as wise as they are tough. i have never seen a blackie go out of sight with two lungs hit, a friend that shoots the wrong kind of bow got a complete pass through on a big brown both lungs, there was blood waist high on all of the alders but he went hundreds of yards in brush that you would expect only hogs to run through. I would consider them two different worlds when it comes to follow up even with a perfect shot.