RE: Swan Hunting
I've killed a couple over the years in VA and NC.
The choke and load you use depends entirely on how you are going to hunt them. By and large, they are about as stupid a bird as you'll find. If you are field hunting, you can land them almost in your lap. A few waterfowling friends of mine that routinely get them in their fields, are reloading hevi-shot in a .410 (yes a .410) to try and kill one this year. Keep in mind... their shots are about 10-15 yards.
If you are pass shooting, well then all bets are kinda off.
To put it in perspective, the four I have killed I've shot with steel T shot, two with 2 3/4" #6 hevi-shot (Remington) and one with 3" #4 Hevi-shot (Remington). I know guys that shoot them at bayonette range with #2s and guys who shoot them at rifle range with dead-coyote. All depends on how you want to do it. If you are thinking of getting one mounted... better bring your billfold!
Infact, this post reminds me... I need to apply for a permit again this year...