I would try the 64 grain PP, Midway sells them in bulk lots, they come in pale blue boxes, Winchester/Olin brass, the primer of your choice, and Varget.

That said, Kevin Petrzilka took a 203 4/8" B&C buck in 2010 with a 1-14" ROT Remington 788 shooting 55 grain BTs.

Me, I like 60 grain Partitions, but they shoot better (4 me) in 1-12" ROT or quicker twist barrels.

Jeff