Let us know how it goes. My Rami swallows 147gr FMJ, Fed HST 147 and now in small doses, Fed HST+ 147 without issue. When new, it was not liking standard pressure 147 (my preferred SD) so it went back to the factory and they made it right. I guess I would recommend ensuring it swallows std 147gr first, before trying the Buffalo load.
Know your bear sign by its scat. Black bear poop will have a mix of fur, berries, grass, etc. Grizzly bear poop will sometimes contain little jingle bells, whistles and smell like pepper spray.