On Ruger rifles, sometimes playing around with the torque on the angled action screw can better your groups. Its a simple thing to try before doing anything drastic. For me Corlokts are usually very accurate. The Roberts is NOT a cartridge known for NOT shooting well. The last one I had, a 700 Remington would shoot three shot groups usually all touching. This with 120 grain Nosler BT's loaded by Federal.