Absolutely DO NOT use your Turkey Extra Full choke. As noted, HeviShot is even harder and less compressible than steel. Steel generally patterns one choke tighter than lead through the same choke, and HeviShot will be tighter still. You will need to pattern your shells, and you may find that an Improved Cylinder may give you what you want with HeviShot. It depends on the HeviShot size how much choke you need. Certainly I would use nothing tighter than Improved Modified, and only use Steel Approve chokes.