Marc: I lived in the heart of grouse and woodcock country in Michigan for most of my life. Thinking about moving back again.
Many may disagree, but a 2 1/2" 12 bore is fine for grouse and 25g to 28g with a number 7 or 7 1/2 is plenty. I have many good friends who still live in that neck of the woods, shoot English guns with 2 1/2" bores in a variety of guages. They all can carry on lengthy conversations about the best shell, load etc, but that is all part of the beauty of bird hunting - telling tales or discussing "what's best"
To be honest after hunting the gray ghost for 50 years I am not so sure it makes a heck of a lot of difference.
As you probably recall you have to move a number of them to get a bird. A number of friends keep very reliable records, and along with myself we would suggest it really does not matter that much what guage, shell load, type of gun, choke or position of the moon. You need to move 10 - 12 grouse to put one in the bag.
I will leave it to the plains folks to give you advise on wild pheasant. I have always used #6 and 30g in Southern Ilinos. On the other hand I have seen the darn things do a complete somersault after what seemed to be a hard hit, recover and keep going.
Enjoy the grouse this fall, it should be a farily decent season. The low end of cycle in Upper Peninsula was probably 2005. The Woodcock population is still pretty dismal in U.P.
