great info for hunting turkeys, i need to kill a coyote
I think you missed the whole point.
To address your original question...."OO Buck" IS the shot size.
What people are telling you is that you will be missing more coyotes with 00 buck than anything.
The prefered shot choice for coyote hunters are listed in the article you dismissed as being turkey loads.
GC has killed many many coyotes with a shotgun & knows what he's talking about...(He's the guy that wrote that story the link was to.)
If you are serious about shooting and killing coyotes with a shotgun you may want to reconsider reading that article.
If you are not serious about getting good advice from veteran hunters, why bother to ask the question?