I use 7/8 oz. of #8s for quail, same for woodcock but would not hesitate to try #9s. Sometimes use 11/16 oz. of #8s in a .410 for quail.
Don't have grouse here, so I can't say about them. But, for doves I use 11/16 oz. to 7/8 oz. at least 98% of the time. I start out using #8s on doves, but in the late season, when the birds (doves) are more mature, tougher, and fly higher I go to 7 1/2s. Only once in 58 years of shooting doves have I seen the need for over an ounce of shot. That was a very unusual situation.
SRH
