3 inches exactly I am not sure but I am very sure I can hit a prairie dog in the chest to 500. I do it every weekend with my 308 custom m-14. I have gotten them to 700 on the first shot but I count that as luck mostly. We made some gongs out of old brake drums and got them sitting on the ground propped on sticks and I can hit most of them out to 900 first shot. They are 10 and 12 inch though. It all depends if I read the ever present wind right.