ThanksI bought both the front and rear sights from Williams. Their Customer Service folks helped me get parts that worked with each other. Optics Planet and Midway USA also sell some of the items. The Williams front sight is shorter than the original one. The Williams front sight has only one mounting screw compared to the original sight which has two screw holes. You have to get a front sight sized for the barrel diameter. I think it's either the size .630 or .650 one. It's the barrel contour that determines which works. You'll need to reuse the screws for the rear sight, they are METRIC size M6 I think. Since I changed both sights, I don't know if an original rear sight will work with a Williams front sight due to the height differences. Maybe lowering the rear sight to it's lowest setting might work. For the front sight, because the base is different, I cut down the length of a screw to fit the sight mount hole. I have a Red Dot on mine too and was hoping that the sight would co-locate but they didn't. The red dot is too high. You can see the front sight fine but not the rear. Hope this helps.