Concealed Third Fastener


Concealed Third Fastener - An extension protruding rearward from the breech end of a set of side-by-side barrels (above), entering a complementary recess in the breech face and not visible from the exterior of the gun when the action is closed (below). The top of the extension is locked down by a cam attached to the toplever spindle. This extra bite reinforces the gun's lockup beyond that of Purdey underbites alone, because the distance between the hingepin and the hidden fastener is greater, giving it better leverage to resist the flexing forces of discharge.



This system does not interfere with loading and unloading as much as the longer-extended Greener crossbolt or Dolls' Head systems.


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