I pretty much think it's a mute point. Under field conditions there are probably only 1 or 2 hunters out of a thousand capable of taking a shoot beyound 300 yards. Next time you're at the range ,run 50 yards and pick up your rifle and shoot a 4 inch group or less at 300 yards ,I'll even let you use a post like you would a tree.
IMHO with close to 40 year experience hunting shooting at deer sized game beyond 400 yards ,300 for elk and moose, is irresponsible ,there are just to many variables that come into play. I really think gun manufactuors do hunting a disservice by fostering thier 500 yard comparison B.S. when 99.99% of those out there can't shoot well enough to do it.