I wouldn't drill and tap it.To me it weaken it to much.The mount Rebel Hog shows is fine and dandy if the Redhawk has the integral cutouts already.If it does why not use the factory rings from Ruger?I'm not sure what it costs nowdays. Ruger can swap the barrels and install one with the integral cutouts.With the new barrel ,labor and rings you're probably looking about 200.00.The Ruger integral set up is a very strong mounting system.That would be the route I would go if I was looking for a good scope mount.I'm not sure how any of these mounts would work with a Red Dot.I use strickly scopes. I have no experience with the RD's

Ruger Redhawk