I have an old Ruger M77 in 22-250 caliber that I am wanting to replace the scope on; it has a bull barrel. I have purchased a new Vortex Viper rifle scope in 4-16 power with a 44 mm objective lens end. What model rings will fit the factory machined mount(s) on my receiver and what height is recommended for the scope I have chosen? The old scope was a Redfield wideview that was only a 1" tube. The one piece rings/bases were mounted with just one screw through the side of the base. Sort of like a quick removable model.