Picked up a 6mmbr no turn 8 twist barrel about 6 months ago from Urban Rifleman. This is a savage action with a bench rest stock and trigger at 12oz. I have a 22br from UR that shoots lights out and was getting groups that beat these on the first range session. I am working up a long range pdog load with 70 SKBs or Nosler 80 BTs and at 600+, I need to be shooting in the .2moa range. Tried a couple different powders and primers for both bullets and just can't get this to shoot. I get a few groups that show signs it can shoot .3 3 shot groups at 100 yards, but once I validate the groups with 5 or 10 shots, they end up at .5moa or larger. I am now at 150 rounds and haven't found anything close to what I am looking for. So when do you guys give up on a barrel?