Depending how badly it' s rusted. If it' s light surface rust take some 4 Ought (OOOO steelwool) and some oil. Lightly, I repeat lightly go over the rusted area with the oil and steelwool.Do not rub any area to much or the bluing will be removed.Once you' ve removed the light rust clean the area and apply a coating of rust preventative. If it' s rusted badly or pitted about the opition is have it reblued which distracts considerably from the value of your gun if it has any collectors value.If the rifle is badly pitted I would suggest if rebluing have it bead blasted then reblued.Hopefully you can get the handle on this rust before it does to much damage to your gun.
Ruger Redhawk