I have the regular Hercules, and surely they're the same barrel.
I've had superb results, almost pellet-good, with 2:
79 grain EPP/UG
95 grain Neilson swaged hollowpoint. Think they're .358, but they may be .357
I only get about 130 ft/lbs with either due to friction, but looking at what that hollowpoint did to a can of water, that dog will hunt!!