Bighorn TL3 SA + PVA/Rock Creek barrel (6BR)= fit like a glove. I got a barrel vise from Brownells with the switchable aluminum blocks and use a torque wrench set at 65ftlbs. After thoroughly cleaning both inside and outside threads, I put on a very small dab of anti-seize, snug things together, back them off, snug together again to 20-30 ftlbs, back off and ensure no anti-seize is on the shoulder and then do the final tighten. I also use go/no-go gauges for peace of mind. I have another barrel coming from Preferred Barrel (6.5PRC) soon and I hope it fits as smoothly and as the Rock Creek. On a good day, my Rock Creek is about 0.25" 3 shot group at 100 yds. On a bad day, it stretches out to just over a 1/2 ". Being left handed was a big factor in finally deciding to go the custom route as I got tired of having a choice of maybe one or two lefty bolt guns available at my LGS.