I'd try a new stock that is at least pillar bedded. I'd torque the stock properly, then see how it does. Could make a world of difference. It did with my SPS. My uncle has an older 700 in 6mm Remington that he said wouldn't shoot for anything. It was supposedly freefloated by a gunsmith(not properly) I freefloated the barrel. bedded the action, properly set the trigger, and cut about 3/4 of an inch off the barrel and recrowned it. The thing shoots extremely well now. I'd bet most of your problem is stock related.
