A friend of mine has a P-10C. He brought it over this morning and we removed the rear sight. Took the Night Fision rear sight, placed it in the dovetail, and finger slid it in. It went halfway and stopped. You could not push it in any further with your fingers. That's how it supposed to be. He wants them so that will work out for both of us. From this experience the rear dovetail on the P-10F is larger than on the P-10C. Maybe my gun in an anomaly, but just a heads up to everyone out there in case you're considering changing sights.