I hit one once and gave it 20 minutes because I saw blood pouring out of the wound,I bumped it another 100 yards after it had layed down. It bled out, but if I had it to do over again I think I would wait at least 45 to 60 minutes unless I had seen it drop. I hunt mostly wooded areas with some fields on the edges and of course they run into the woods not the fields most of the time it seems. The next one I gave 45 minutes it had bled out not more than 60 yards from where I hit it,that was an easy recovery. I guess every new hunt requires a different response but I have seen good results for most people who let them lay for a while.One thing that would cause me to give chase quicker is If coyotes are thick in the area,I would not feel good about leaving it lay very long in that situation.