Jerry, the screwgrip action provided a very strong third bite and can be clearly seen in these photos of a Army & Navy (Webley). Hints that a gun is a screwgrip are the large diameter of the top lever head, the locking screw on the top lever screw, and the rib extension reaching all the way to the top lever.These are all characteristics of the action. Note the square threads on the spindle shaft--that's the screwgrip. (gun made in 1921)

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