You could glue an XS Big Dot shotgun bead directly over the factory bead, but if you use the ghost ring rather than the receiver, I expect you will still shoot high. The front and rear sights must be equal in height relative to the center of the bore. A ramp or pedestal mounted under the bead, that is high enough at the front of the long tapered barrel, to match the height of the ghost ring, will be hideous. A better option, if the ghost ring is permanently mounted, might be a red dot optic.