I would stick with a bullet in the 180 range. The 06 has always performed better down range and on impact with at least a 180. The difference in felt recoil between a 150 and a 180 is 2.5-3 pounds of recoil energy at most. The tikka is only around a pound lighter than most of the other box rifles out there so the recoil isn't as bad as one would think, especially from a 30-06. That being said bullet choice comes down to what your gun likes? Try some Accubonds, Barnes trippleshock, Berger, or if the core locks shoot well use those!