The last time i shot in competition at 1000yds was at Manatee. And took second in a shoot off having been beat by a 7mm rum. Actually that happened twice and i got beat by the same LAWYER. It seemed to me the 6mms were great when there was no wind, but the bigger longer bullets worked better when the wind blew if the had the speed to take advantage of the higher BC. I think unless you can predict the weather you need one of each. When a 6BR or BRA hits steel at 1000 got to watch close to see any movement, my 300 grain SMKs were another story. The man that let me shoot his rifle at first time i ever shot at 1000yds or over told me, " At longer ranges you only have 2 friends BC and speed and you need to use both."