6 SRB, 6 Dune, 6 RAT, 6 FATRAT, yadda.... It's a great idea for someone with a PPC boltface.
With Randy's 95, I use a standard 6 BR, 10 twist, with ~ 30.7 grains of Varget. You really need 104 thou freebore.
If your 6 BR reamer has less, say 85 thou, try the Berger 90 BT. I shoot it with...