What internal parts do you need to polish to smooth out the action on a P-01?? What should I use to polish the rails rails and sear?
You do not need to go anywhere near the rails and there's nothing in the sear cage to polish either. Polish things like the hammer sides, trigger bar where it contacts the frame, inside the frame where the trigger bar rides, The hammer strut can be polished up as well. I use 2000-3000 grit auto body paper. You want only to polish and remove no metal nor change the contour of any parts. If you go too far you'll have a gun that won't run right and could be unsafe.
You can call CGW and they will walk you through most of this and they also have a tutorial on their website.