I had the same issue with my 300 wm. Had to cooper clean the barrel i used to shoot 168 smks in and then the 168 ttsx and 150s ttsx worked awesomeI can not get California required copper bullet loads to group up. I can get 1.5 MoA grouping but get sub 1 MOA has proved elusive with full copper bullets.
Anyone else having this issue?
I’m having the same issue regardless of the caliber
300 weatherby, 30-06, 6.5x284, and 243...
Lead I can throw 3 and all three will be touching, copper bullets string out all over place.