Well, first off I don't know why you would ever use that amount of shot. I have used exactly half that much and taken dove pheasant duck and geese as well as turkey, get some 1 1/4 and some 1 oz wads and pattern your gun [a big piece of card board and a roll of butchers paper] try several different shot sizes to see what the gun likes start with the same volume of black or pyrodex as the volume of shot and work down ward when you get the proper pattern for the choke of your gun you have your load.
A couple of points: a black aiming dot with marking pencil and a string with a tack on one end and a pencil on the other I usually use a 20 inch so I end up with a 40 inch circle to check the pattern.
A selection of wads from a reloader would be a big help its had to tell which ones will shoot best in a given gun.
Hope this helps Lee