If the elk is standing or wiggling I shoot again. However I often hunt near Yellowstone Park. If a wounded bull crosses from the National Forest into the Park then he is lost as the hunter must forsake the animal. Even if you see him laying a few yards on the Park side of the boundary it is a federal violation to recover the animal. Sad but true so I want my bulls to go down quick and stay there. I shoot until they comply and usually with heavy for caliber bullets sometimes of rather large diameter.