I've had Raptor and EGW single screw RDS mounts on Rugers in 44 Mag, 45 Colt, 357 Maxi and BFR 454. All worked perfectly except the 44 Mag which sheared two screws before I had it d/t for a second screw. I think the Raptor mount was a loose fit in the rear sight channel and that caused the screw to shear. I'd try any new mount with just one screw first to see if it held before I d/t a gun for a second screw.
Someone, and I don't remember who, is making RDS mounts that uses the rear sight pin to help secure their one screw mount. Sounds like a good idea to me.