[quote=DLA].... The entire ejector mechanism appears to be located in the barrel lump and I do not see anything else that interacts with that mechanism. The ejector is activated every time the gun is opened. ...
There is usually a sear for the mechanism to trip the ejector that has a slightly extended 'foot' out the side of the bbl lump.
Usually the left side.
That foot engages a shelf inside the frame as the bbl is opened and pulls the sear downward,,That releases the ejector itself which is under spring pressure and snaps rearward.
Closing the action/bbl pushes the ejector in and recocks it. The sear reengages it and holds it with it's own small spring giving it engagement.
Removing the bbl from the frame..forend off,,allows the bbl to slip rearward just enough for that foot to miss the frame shelf. That keeps the ejector cocked when the bbl is taken down from the gun,,or is supposed to. Some will release at the slightest mmovement when they get worn.
Also a good idea just like a SXS or other ejector breakopen to place your thumb over the ejector to dampen it when it snaps out if there's no shell in the chamber. The cross pin that limits the ejectors travel takes a lot of shock as does the spindle of the ejector blade if not done. The springs are pretty stout in them as a rule.
It's not a Parker,,but no use damaging one for no reason.