There are at least a few writers on that list who could (and would be willing to) kill a big game animal at 600 yards. In fact I know that John Wootters shot at least one animal at around 600--before there were laser rangefinders and all the rest of the stuff that helps a lot these days.
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.” John Steinbeck
