I would take into consideration that in Mr. Foster's day the birds were far more plentiful and one could pick and choose his shots. Unfortunately this is not the case in grouse country (or any game country) today. Also I don't shoot a 1oz load but stick to 7/8 in my 16's and if the woodcock flights are in I like a 3/4oz load in the 20.
What works for one person might not work for another but 8's early on and 7's or 71/2 in the later portion of the season has worked for longer than I care to admit
