maybe instead of making a traditional block, you should try embedding the hair in plastic and have the hair come out the front of the mess like they do at the Coda factory. Yes it will push up on the pearl slide but the makers don't seem to care so why should you?
If the screw is bottoming out at the end of the hole, it can't pull forward and work its way out of the adjuster. The pull of the hair is being supported by the stick and not relying solely on the gripping force of the adjuster. There are many bows where this is not the setup, but I find this arrangement to work best.
My feeling is that if the screw is properly supported then it has no reason to pull itself out of the adjuster, but if it is not supported then the likelihood that it will pull out is much greater.
Usually it's more than a fraction of a millimeter. Also if the end of the screw is rounded, why would it drill into the wood? And if the screw was drilling into the wood, the hole would end up being exactly the same length as the screw, not longer
Often the adjuster will come off the screw because the screw is shorter than the hole it is going into. If this is the case then simply gluing the screw back to the adjuster is only a short term fix. It may be that the stick needs a bushing to support the end of the screw and keep it from pulling out of the adjuster again.
When the silver underslide comes loose from the frog, what is the preferred glue for joining the two ? I've used hide glue in the past but sometimes it will come loose again and so I wonder if anyone has a better suggestion.
Ive seen a few soudposts with strings attached (I'm not far from WV haha), I know these are for setting up the posts but I've never understood how this method works. Anyone feel like explaining it to me ?