More first hand, real world , results.
7WSM 180 Berger takes down two Grizzlies!
This is with 180's from a 7 but definitely data that should interest you for this hunt.
As for a 30 cal option. I have taken Blacks with a 210 LVD, but never a brown or Griz. That said if it were me, and I was taking a 30 cal, I would load the 230's.