The latest data on what cartridges the long range shooting crowd is using is available
here.
The competition was the NightForce sponsored Extreme Long Range Steel Challenge, targets are 700-2100 yards from the shooters location.
Looks like the cartridge used the most by the top 10 finishers was the 300 Norma, used by 4 of the top 10.
6.5 PRC was used by the most competitors, 12 of the 103 competitors answering the poll, but no one using it finished in the top 25.
6mm Creedmore was used by 4 shooters, as was the 6.5 Creedmore.
This contest isn't part of the precision rifle series, it's a one-off competition for extreme long range shooting. Surprised by so many people (15) using the 7 SAUM and 6.5 SAUM, and at how well they did with 6 of the 15 in the top 25 finishers.