Marc,
Congatulations. We live in a beautiful state not only for hunting, but, fishing, as well. I can't believe how blessed we are. Let me know if there is any direction you need for any Minnesota outdoor pastime, and I'll help as I can.
I've shot half a lifetime at the resident birds, and will note the following. Grouse put up less of a fight then pheasants do.
A pellet, or two in a grouse is usually enough to get them on the ground, where the dog takes over. A few of them have tried to hide over the years, but, it is never the track meet that you can get with a pheasant, and a dog makes all the difference, anyway. In my experience, ruffed grouse don't run as fast, fly as far, or cling as tenaciously to life as a wild pheasant.
Having said that, you might find it odd that I often use the same gun (a Tobin 16, with IC and MOD chokes) and, the same load (Eley fibre wad 1 oz low pressure English 5s and 6s) interchangably on grouse and pheasants, particularly early in either season. But, the truth is, the combination simply works. I'm not a 40 yard shooter on wild birds of any sort, typically, so I suppose any of the big three (12, 16, or 20) would be fine for my use.
And, I have used all three for same. Usually, good quality, store bought 1 1/8 in the 12 will be all one needs for either bird, if that is the gauge you are using. You said the gun was 'kinda heavy, so recoil won't be an issue.
Carrying it all day might be, but, thats a different story.
Welcome to God's country. Enjoy.
Best,
Ted
