Choke is a performance - this is definitional. Choke tube makers and shotgun manufacturers tend to think of choke as a constriction for self-serving, albeit sensible, reasons. Probably the worst approach is to think of choke as whatever is stamped on the barrel.
If the gun fits me, the downsides to full choke patterns for pheasants are the risk of pink mist on close shots and a diminished chance for success with an incomplete gun mount. I can get around the first with a combination of patience and inexpensive promotional loads. I can manage the second only through the discipline that comes from practice.
If I could have just one field gun for upland use it would be my pre-war solid rib M-12 16 nominally choked full (measuring .021). With B&Ps I get better than 70% patterns. Rem GLs give perfect mod patterns. Soda straw inserts bring this down to IC. I have figured out that further opening to cylinder and skeet patterns adds nothing to my scores or field success vs IC - even in grouse/WC woods. But, FWIW, Polywad spreader discs get me to somewhere between cyl and skeet patterns with this barrel.
Sam
