Originally Posted by cblowe13
Can you explain what using that on the bottom of the sight will do
You would make a couple of punch marks on the bottom or a bottom edge of the sight. Using the punch will displace some of the metal up and outward from the surface of the sight, as it makes a little crater like divot in the metal. It is a property of metals that it will tend to flow up and around a punch, kind of like using dies to make coins.
That should effectively give you some few thousands of an inch of metal back above the smooth surface and create an area that will bite back into the slide dove tail.