I use the steel Leupold Weaver style cross slot bases on my 458 MK-X and the same Weaver ( I think # 46 and 45) fit virtually all the M-98 actions.
I also use both styles of the Leupold QR rings ( the ones with the levers on the rings, which are heavy, and the one's like the old Rigby style with the levers on the bases) and have had good results with all of them.