I currently have a B&C medalist but after tromping around the weight seems heavy after a while. Would it be a good or bad idea to exchange the B&C stock for a factory plastic stock and just pillar and bed it instead?
Probably not. It would take quite a bit to get the plastic version to the stiffness of your B&C. You might look at a light weight carbon fiber stock and pillar bed it. I just replaced the same stock on a .280 with a Manners and am well satisfied with it. Your budget will decide which way to go, but the plastic does not lend itself to bedding without a lot of extra steps and re-inforcement.