Thought I recalled that John Alden Knight talked about 10's for woodcock in his book on the birds. (9's being the other size he recommends--but then he also wrote that a 26" barrel will lose 15% of its muzzle velocity in comparison to a 28". Not sure where that came from.) I checked and found my memory wasn't deceiving me. But I can't recall any mention of 10's for grouse, from any writer in any of the books I have.
Zutz always tended to recommend tighter chokes and larger pellets than most people who hunt over dogs. (As Ted pointed out, Zutz hunted dogless unless he was with someone who had a pooch.) But Zutz also had pretty fair shooting credentials, as a Wisconsin state skeet champ (multiple times, I think). On the other end of the spectrum, you've got George Bird Evans, a dog man to the core. From his writings, I'd say he wasn't a much above average shot, which may explain why he favored quite open chokes and an ounce of 8's. Coupled, of course, with assistance from very good dogs.
