Sierra recoomends 73.4 grains of IMR 4350 with the 190 grain Matchking. You can call Sierra at (800) 223-8799 and get some one-on-one advice from one of their "ballistic technicians." They are open M-F from 0800-2200.
I have had excellent results with RL-22 and RL-25 (Federal 215 primers, Weatherby brass) - my rifle likes a fairly stout charge for best performance. Best work up to the max in your rifle but these powders are worth a try.