I remember way back when when I stopped shooting High Power and started the LR Field rifle game everyone told me there was no way a 6mm anything would be competitive. I had to use a 308 or 260.
Take a look at the top 20 PRS results.
Now I have no idea if Ruger is using shit 6mm barrels or what, but there is no way I would use anything but a 6mm something for a new build. Either a 6x47 Lapua or 6 Competition Match. Get some 105 Berger Hybrids or 115gn DTAC (Sierra) and go to the races.