One thing that many people overlook that you might want to try is loosen all of the action and lug screws and tighten them all to an even and snug pressure. If the screws are tightend too much they can sometimes create a little torque on the action and you could get less than good accuracy. This may or may not help but it's worth a try. Also make sure that there are no little points of wood that are touching the barrel down the barrel chanel.