Here is a page of shotshell sizes.
From a thread on another forum.
If you do not want to purchase a Carlson Deadcoyote choke tube. Use a full choke tube that has a .690 constriction on it. Many of your chokes have the decimal constriction annotated on it. It's right between Full and Extra Full on some guns. For example the Win Extra Full has an constriction of .690.
Win Choke X-Full #12216 .690 constriction
Click on your name brand here and see which one is close to the .690 constriction.