You mentioned using Barnes TTSX bullets. I've found that Barnes TSX bullets tend to produce copper fouling in my .270 Win. Pressures and velocities increased and accuracy suffered. I switched to Hornaday GMX (gilding metal) and solved the problem.
People are like rifles. Some are tried and true, having great eyes, personality, and fun to be with. Others never seem to hit the mark with you. Still others go off half-cocked. Still, it's nice to know most of them.