While I dont condone shooting 500 yards with any caliber without an extreme amount of practice, especially with a caliber like a 243, I know it can be done. Go to www.longrangehunting.com, theres guys there that shoot all kinds of animals at extreme distances, but they use guns that are adequite for the task.

btw, my favorite caliber is 7mm08, shot a doe and an 8pt last Friday morning, the doe dropped in her tracks and the buck ran about 50 yards and fell in sight.