Got here late, sorry.

I found by pulling bullets that factory RWS 9.3x74R is loaded with Norma 201 powder (about 52 grns.). That's the only powder that my rifle likes. Also, for messing about and load develpment Speer bullets are quite inexpensive. For larger game, I think I would keep at it until I found a few more bullets that regulate. The Norma Oryx is a nice bullet and now Hornady mades loaded ammo too, which I have not tried. Good shooting.

C.