I'venever hunted grouse before.....mostly a quail hunter. But it is my understanding that grouse hold tight and are in more dense woods (and treelines?) than quail. In this situation, an IC for your first shot and maybe a modified for your second. When I'm quail hunting I typically use an IC and a modified. BUT I have been known to use a Skeet and a modified as well and in my honest opinion I really think this is a great combination for quail. It might work for grouse.....if what I hear about them being in tight cover and holding tight is true. Just my $.02