I have been interested in finding an upper for my M-4 lookalike in a caliber with more punch at 300 yards than 5.56 provides. The 6.5 Grendel data I have found has been zeroed for 600 yards as the table presumed the shooter is into 600-1,000 shooting. At least that's my guess. Those tables show a mid-trajectory altitude of 45-55 inches, which strikes me as odd for a round touted to be "flat shooting." All of the other calibers' ballistics data I have found is based on a zero of 200 yards (except for 7.62x39 at 100 yds). Can anyone provide a pointer to data that would impress me a bit more?