Stripped encore barrel holes

[MaxKW]

I just received a short 500 S&W barrel and the forend screw holes have pretty flat threads, I was going to rethread bigger but it's very hard to do it with a regular tap because the holes are so shallow, and I don't feel like welding a small nut is the proper fix, is there any way to do this with a epoxy or putty, I have access to all types. I'm thinking of putting a release agent on a bolt and building up a small dome around it. Any thoughts?

 

[BCRider]

What you need is a bottoming tap. That way the short depth doesn't matter.

I've even taken off the very slight lead taper found on a bottoming tap on occasion to get it deeper. Just remove about 10 to 15 thou on a grinder. Then using a sharpening stone replace the lead on the first turn later on.

You can maximize the thread depth by first drilling the tapping hole than re-grind the tip of the tapping drill so it's flat ended with a little lead angle on each side. Use it to get that last one turn of threading. Between a flat ended drill hole and the modified bottoming tap end you should be able to get the 3 turns minimum engagement needed if you're going to use a fine enough thread pitch.

Forget about the epoxy. It has its purposes but for something this small and heavy hitting you won't have any joy at all with simply dabbing in some glue. It'll all rip out the very first time you pull the trigger even if it doesn't do so just from tightening it up in the first place.