OWD -
This thread was titled
When is a sidelock not a sidelock???
by you.
It is my sincere hope that the info below, again from the Hallowell website, might at least partially help resolve your question:
Boxlock - A type of action (receiver) for a break-open gun where the lockwork is contained within a box-shaped housing. (see also: Sidelock). A boxlock is superior to a sidelock because although more metal needs to be removed from the action body, less wood needs be removed from the head of the stock---and wood is generally more vulnerable than metal. The Anson & Deeley boxlock, patented in 1875, the simplest, most reliable and most successful action design, is identified by two pins spanning the width of the action, one at the bottom rear and one slightly forward and higher, upon which the sears and hammers, respectively, rotate.
Sidelock - A type of action on a break-open gun where the lockwork (hammer, sear, mainspring etc) is mounted to the back side (inside) of a plate (or pair of plates for a double gun). A sidelock is superior to a boxlock because: 1. Less steel needs be removed from the bar of the action; the action is therefore stronger. 2. The lock plates provide a larger canvas for the engraver's art. 3. Sidelocks have generally been considered a more aesthetically pleasing form. 4. They are often made with secondary, or intercepting, safety sears. 5. Trigger pulls theoretically may be adjusted more precisely. 6. Because of all the above, most makers building a range of guns have usually reserved the sidelock action for their better grades of guns; this last being the most relevant reason why sidelocks are generally considered superior to boxlocks.
Sideplates - Decorative steel plates mounted to the sides of a boxlock break-open gun, inletted into the receiver and into the wood just behind it, to make the gun resemble a sidelock in appearance and to provide a greater area for engraving. Sideplated guns, usually, can be recognized by the lack of action pins visible in the sideplates (although some sideplated guns are built with fake pins).
In the event any of my posts on this thread were found by
you to be anything but sincere, I wholeheartedly apologize. I'm reasonably familiar w/ one brand of SxS guns, Francotte, and this thread caught my eye because that name was used by one of the early 'responders'.
