IF you are going to waterfowl hunt, you need non-toxic shot. I suggest for the number of shots fired, that you use BISMUTH instead of iron/steel or tungsten.
IF'S:
If you use BISMUTH you get to load it the same as if using lead. BISMUTH has almost as high a specific gravity (weight) as lead and works beautifully.
If you use hard shot - tungsten, iron or steel, you should use the thick walled plastic shot cups.
If you use the plastic shot cups, you will need to use something - ie: a couple 1/8" thick card wads between the plastic and the powder, to prevent the flame from melting the plastic and coating your bore with it, as happens with unprotected plastic shot cups.
BISMUTH shot costs more than steel, however you do not have to buy plastic wads for it's use.
imho