My friend's daughter uses 70 grains of JSG and a 240 grain XTP. She's taken several deer with that load and it has performed nicely. Now JSG isn't as hot as T7, with T7 or BH 209 I'm guessing that 60 grains would equal to or exceed 70 grains of JSG.

I wouldn't go lower than 60 grains though, and keep the shots close.