I've never miked a 20 or 16ga standard Sterlingworth that had less than 10 thou factory choke. Even the 26" guns tend to have 10+ and 20+, or a minimum of what would have constituted IC/Mod when new.
I haven't miked a 30" 20ga SW, but the several 30" A grades were all full and fuller. Whereas 24 thou is accepted as Full in a modern 20, I've seen 36 in the older ones.
I just acquired a Sterlingworth 20ga that I miked at .039 in the L barrel! Most folks did seem to like a lot of choke in the older doubles, but I've seen a few Ithacas--I think all Flues guns--choked cyl and full. (0/4 in the Ithaca choke code.)
Researcher, thanks for the additional information on Sterlingworth SN's. Makes sense that they'd block the "specials" such as the Wildfowls and Skeet and Upland guns.
