22 LR, hit em in the head! If you don't have a 22 I would go with 7 1/2-8 in a 12 and 6 in a 20 gauge. As far as Grouse go I have used 4-6 shot in a 12 for Prairie Chickens - Grouse. Dove and small game opens Sat. here, I can't wait! Happy huntin' everyone