This is the stuff for soldering on front sights, super easy to use with a propane torch.
The picture shows my first tube of the stuff with copper in it, my next purchase was the same low temp silver solder without the copper.
To put on your front sight you first put a piece of sandpaper over your barrel grit up and run the sight back and forth over the sandpaper to get the sight base perfectly matching the barrel curvature.
Next put a triangle file on a flat surface, with your barrel resting on the top barrel flat , drag the barrel across the triangle file. This will make a perfectly centered line to use as an alignment reference for placing your sight.
Put some solder paste on your sight and hold it on the barrel with some kind of clamp aligning it with your previously marked center line. Heat the sight briefly until you see beads of solder melt and form around the sight and you are done.
In this picture I am doing the same procedure with a underlug on a fowler barrel.
You can see my file drag marked center line on the barrel. With a C clamp you can tap your sight or underlug around a little for alignment before you heat it and melt the solder.
