Like I said - 300 yards is easy, even on deer - if you have the capability at that range, from hunting positions.
; I don't believe anyone should be shooting at our big game any further. Too often - "ran off without even flinching - missed him, I guess". Then, there is no followup and even if they did go to the impact site, with the angle of the bullet and range, there probably isn't an exit wound, therefore no blood trail and few who would take such a shot are likely to trail it for even 50 yards, let alone further.