Or maybe, after drilling off the action screw heads as short round suggested, turn the rifle upside down and whack the heck out of the stock around the pillar areas with a 1- or 2-lb rubber mallet. Then put the stock in a vise, using leather or rubber to cover the jaws, with the bottom side up. Take a 1/4" punch and a ball peen hammer, and start working alternately on the action screws, going gently at first and getting more serious as needed. Make sure you have removed all of the head off the screws though, or else you'll just drive the pillars out of the stock. You may end up doing that anyway, but if so, you should be able to just unscrew them from the action with pliers once it's out of the stock.
I'd be more concerned with trying to save the action than the stock or the barrel, as it's by far the most expensive piece. Good luck.