When trying those Barnes tsx, you'll need to clean the bore often. I have them shooting well from my 223 but 15 rounds and the bore is copper fouled, they start spraying all over, clean it and I have groups again. In my guns,,the TSX likes ALOT of leap, The advise I got local was seat to the center of the forward ring,,it worked.
Wise choice giving up on a long projectile in a slow twist, it's kinda why they make different barrels. The physics behind it is nothing new.