I've got a .280 Ackley with a 22" Brux, 1-9 twist, shot suppressed 100% of the time. My loads are all with Nosler brass and CCI BR2s, velocities are with a Magneto speed, also in an accurate node. More speed has been available, to the detriment of accuracy many times:
RL-26, 160 accubond at...