A better pad and making sure the stock is seated in the correct part of your shoulder should help quite a bit.
What he said. Try a Pachmayr Decelerator Pad. I have one on a Model 70 30.06 and a Model 70 .300 WIN. Mag. It does a great job with those rifles and I shoot 180 grain bullets. One thing that might be helping me though is the weight. Both rifles are probably 8 pounds plus.