Locktight or other makers offerings like screw lock, from maker to maker I have found that some potions have a vice like grip while others no grip at all. So my recommendation would be a drop of common or garden super glue to stop the screw undoing its grip can be overcome easily.
Wood Screws working their way out of guns like you describe, do have a simple cure used for many years. I am sure the late Jack Rowe would have used it many times because it is a common fault on some older guns. Just put a few drops of French polish or Rosin dissolved in Alcohol in the hole and while still wet put in the screw, it will act as an adhesive but the bond is easily broken with a screwdriver.
