DW, there are so many variables to that question. Are you mostly shooting ducks decoying (wings cupped, feet down) , or are you pass shooting(ducks flying by). what size choke are you using? I have a 28 inch barrel on my SBE and use a Carlson extended Modified choke tube. I use mainly Federal 3" #3's somewhere around 1 1/4 oz at 1500 FPS. This is my personal preference. If mainly teal are decoying (which happends quite often) I might run 3" #4's.