The general rule of thumb for shotloads is to use an equal amount of powder and shot, and then to make adjustments up or down to improve the shot pattern. 80 - 100 grains of shot and powder in any combination should work just fine as a starting load (i.e. - 80 gr. powder + 90 gr. shot, 90 gr. powder + 100 gr. shot etc...)
POWDER MEASURE SETTINGS TO
MEASURE OUT OUNCES OF BIRD SHOT
50 grain setting = 3/4 ounce of shot
60 grain setting = 7/8 ounce of shot
70 grain setting = 1 once of shot
80 grain setting = 1 1/8 ounce of shot
90 grain setting = 1 1/4 ounce of shot
100 grain setting = 1 3/8 ounce of shot
110 grain setting = 1 1/2 ounce of shot
120 grain setting = 1 5/8 ounce of shot