I shoot federal gold metal match and reloads only. My hunting load is GMM brass, 45 grains Win 748, 165 Nosler partition, Federal 210 M primer, and I load .000" off the lands. But, I shoot a bolt gun. Just starting to look at T/C's. I suspect the 180 grain doesn't do well in your gun due to twist rate. Probably can't stabilize the bullet. Most 308's I've come across seem to like the 150 to 168 grain bullets.
Good luck