What would have been the original chamber length of a Fox Sterlingworth 16 gauge manufactured in 1921?
Would measure 2 1/2 to 2 9/16"
In theory they should be 2 7/16 inch, intended for the then "standard" 2 9/16 inch 16-gauge shells. Fox doubles could, of course, have been ordered for the longer 2 3/4, 2 7/8 or 3-inch shells. Pretty unlikely in a Sterlingworth though. Fox chambers often tend toward the tight side and an industry standard chamber gauge doesn't go in to the full depth.