Brew:
First of all, welcome to the Forum.
I have not used the Black Hills 115 EXP ammunition in my R9. I personally would be inclined to stick with proven fodder for the "pup," such as 124 or 115 grain Speer Gold Dots, until I was sure that the EXP was not loaded to +P pressures. The R9 pushes the size/weight envelope for its caliber, and there's a reason for the warning against feeding it +Ps.
Good luck with your "pocket rocket."