Almost makes me wish the late Burt Becker was with us, to give his insight into this question. In re-reading Jack O'Connor's Shotgun Book- the chapter on chokes- he mentions that Winchester's WS-1 and WS-2 were based on a slightly different radius that the standard Imp. Cyl., Mod. and Full Winchester chokes. My 1939 M12 28 gauge has a solid rib and is marked WS-2, but it is a field grade, not a Pigeon Grade skeet model (like my friend has-- his has the WS-1 choke markings. Any Winchester M12 addicts on the forum care to elaborate on this a bit? RWTF

"The field is the touchstone of the man"..