Barrel extension screw

[B. Dudley]

There is physically no way that the extension screw can back out on its own. It is screwed down tight, then the head machined off flush the the rib to eliminate the slot and then everything is soldiered in place. If something is amiss, then it has been fooled with. Maybe the extension replaced or repaired.

[hugh rather]

I think you are right.May pass on this one.Thanks Brian and Dean.