I just purchased a 30-378 Accumark a few weeks ago. So far I've tested 180 accubonds and 200 SMK's. I've also tryed H50BMG, RL22, H4831SC, & H1000.
My rifle loved the 200 SMK over 117 gr of H50BMG. .3" group at 100 yards. I hope to crono them next week.
I've also heard some very good things about the 210 berger bullets.