While reading a book written by a grouse hunter in 1898 New England,"Hitting Vs Missing With the Shotgun" The author mentioned that his favorite load was as follows:

"The charges that I have used for many years in a 12-gauge seven pound cylinder bored gun, with entirely satisfactory results, are, for the right barrel-which I nearly always use first-three drams of good black powder with five-eighths of an ounce of No. 10 shot, and for the left barrel the same amount of powder with seven-eighths of an ounce of No. 8 shot. These charges give good penetration and pattern, while the recoil is scarcely
noticeable."

I mentioned this before, (a couple of years back) and the general opinion was that the author was most likely a market hunter that shot the bird on the sit.
I have found out since that He (S.T. Hammond) was a very well known and respected sportsman.
I would not have thought that #10 shot would be enough to kill a grouse, but it did.
Was the #10 shot of 1898 the same size as the #10 shot of today?
Maybe the birds flushed much closer and a fast shot could hit them at 10 or 15 yards.
The three-dram load of a very light shot charge and very small shot, must have opened very quickly.
What do you experienced grouse hunters think of this?