RE: Buckshot
Buckshot is a great close in stopper! I've heard it's used tracking wounded leopards in the bush in Africa as a close range stopper, but I'm no expert!
I've shot deer myself with it out to 60 yards very effectively. It makes it much easier to shoot a deer on the move. A good hit and the deer just fold up!
I must stay though, I use 000 (.36 diameter), not 00 (.33 diameter) from a long barrel full choke to increase the pattern and effective range. A word to the wise is my experience is that buckshot doesn't shoot well from a full choke 'tube', so I have a 30" fixed full choke barrel for it.