When you're customizing a Mauser rifle, one of the most common jobs is to weld up the locking screw holes in the trigger guard.
With the locking screw holes in place as filler material, we'll use a TIG welder to fill the voids.
Dress the weld down with a coarse round file and finish it up with a fine chainsaw file, then reposition the guard and dress down the front screw weld.
If the weld runs into the screw hole, clean it up using a piloted counterbore, a drill press, some care, and patience.
That's all there is to it. We used a TIG welder, several files, a counterbore, and a little handwork to plug the locking screw holes.
-- Larry Potterfield