I have a S&W 642 with an integral front ramp sight (not pinned). My eyesight ain’t what it used to be so I decided to get a XS Big Dot made by Trijicon and install it myself. A little elbow grease with a couple files and some fine grit sandpaper and this is what a got so far. The replacement sight was black and didn’t match so I sanded off some of the paint on it. I’ll probably clean it up a little more, but I like it so far. Much better sight picture. Need to test it at the range.