LE No. 4 Mk. 1 Front Sight

[albog]

I need to loosen the "reverse" screw holding the front sight blade on LE No. 4 Mk.1 to adjust or replace the blade. One of the threads suggested to make up a special tool for that as the original tools are unavailable. I made up three of them following the thread instructions to a tee, one of the tools was made on precise measurements of the screw diameter and rib thickness by a digital caliper in a professional machine shop. None of them work; cannot move that screw an iota and the slot sides of the tools are grtting stripped. Could it be that this screw is set in loctite? Or is there a special procedure to do this? No time to go to a gunsmith for something like that.

Appreciate any advice.

 

[purple]

The screws work so well that I would see no reason to use Locktite to secure them-but you never know. The screws can sieze up from rust and/or accumulated crud,so you could try treating it with Kroil or another penetrating oil and letting it sit for a day before attempting removal. If the screw remains siezed after the penetrating oil soak you can tap it on the face with a punch with the aim of dislodging it a bit. If nothing else works the screw can be drilled out and replaced.

 

[woodchopper]

as per above, good penetrating oil for 2-3 days and a little heat might help, hot but still touchable, not burn your hand hot or burn off the oil hot.

If that does not work, before you go the drill it out route try a lot more heat, use a torch to heat it up, burn oil hot, but not glowing hot, use a wet rag on the barrel to keep it cooler. This should heat upset the parts but not effect the temper, once its cool try the penetrating oil again.

 

[louthepou]

On one occasion (before I knew about that screw!) I used a punch to drift the front sight blade. It wasn't that tight and moved... So I didn't need to unscrew anything