I use screw chokes about as often as Stan does. If I need different chokes for a different course, I shoot a different gun or change chokes at the beginning of the shoot and leave them there. My biggest win in sporting clays was when I entered the course with my .410 equipped with modified and tight modified choke tubes. I had a handful of 3" shells in my bag for the really long shots. At that event, no ammo restrictions were in place in the .410 event. I ran the birds on the first station and was so ecstatic over my success that I forgot I had choke tubes or 3" shells. I won the .410 event overall with tight chokes and 2 1/2" shells and never looked back. I won't identify the shoot, but the competition was pretty rough for a non competitor like me.