I hit a doe at ten feet away on a small two person drive. The shot was face on and I burried the arow to the nock in her brisket, into her lungs. I thought she went down but decided to wait 1 hour. I found lots of pink blood with air in it but no deer. Lost the sign after 1/2 kilometer (thats Canadian eh). Couldnt believe it. I think it depends, in this case the deer was already scared and running as apossed to just feeding or walking through.