Just got back to reality! 5 weeks in MN hunting Ruffs and Pheasant. What a great year for Grouse, outstanding at least where I was. To the OP's question, shot all grouse with a Cyl. choked 1100 and a SKB 100 choked SK/Mod, both in 20Ga. Shot wild pheasants with the same guns. Number 6 shot for all. High end copper plated 1 Oz. for the Pheasants though. My usually pointing sometimes flushing dog at least stayed close enough, mostly! Was excellent on retrieves, the best part!
Ted, no need to wait for a freeze, slews are dry, leather boot dry. Now the Vikings? Well, you know.

Chief