So, Dennis is calling 'trigger plate action' and 'droplock' designs a subset of 'boxlock'.

That's correct in as much as the actions are contained inside the 'box' of the frame as opposed to the obvious 'sidelock' designs.

I'll buy that I guess.

The other descriptive terms elucidate refinements.



"The price of good shotgunnery is constant practice" - Fred Kimble