If I haven't made the shot in practice, I don't try it at an animal.
If you've proven the distance you can make the shot and proven when you can't, your limit is a known.
Otherwise, why set an arbitrary limit?
"Camping places fix themselves in your mind as if you had spent long periods of your life in them. You will remember a curve of your wagon track in the grass of the plain like the features of a friend." Isak Dinesen
