I have killed several elk and a few deer under 20 yards. The 06 or 300 WM are very effective at that distance. My closest ever, was a 5 point bull playing possum. He was on his feet, on my side of the 5 yard line. It works best however if you "open" both eyes. I passed on a cougar inside of 30 feet one day and a fox inches away. I have a picture somewhere, of a young Pine Martin sitting on the ground next to my boot. I don't believe it had ever seen a human. He wandered off after a 1/2 hour or so.