Before I moved to Oregon, I had access to some hayfields in Bullock County, some with shots over 600 yards. I would hunt them from ground blinds set up to watch along the edges. To prepare, I made a life sized deer silhouette from heavy cardboard, set it up and shot at it from the blind, sitting on a stool and shooting over crossed sticks. I did not put any bullseye on the target, just shot for the shoulder or behind. From that experience I decided that 300 yards was my practical limit. Whenever I set up to hunt, I would range the treelines and pick landmarks that would keep my shots inside 300 yards. I will add this advice--if you shoot one that doesn't drop, try to keep focused on where it ran back into the woods, so you have some idea on where to start looking for blood.