Some courses are set up with longer shots than others. I would prefer to shoot every course with #9 shot and an improved cylinder. The beauty of sporting clays is the ammo choke combo that works great at your course isn't so great at my favorite course. When I go to a new course I take a 100 rounds of #71/2 and 100 rounds of #9. I also bring all my chokes. If all the shots are 30 yards or more I need heavier shot to break the clays. If the majority of the clays are under 30 yards I can use #9 shot and a modified choke. Some courses are mixed up and I change everything at each station until I find something that works on that course.