I take it your hunting something bigger than turkeys with 00 buck???

With my 20Ga Model 500, I tend to just stick with the Imp. Cyl. choke. For hog hunting it has always done the trick with 00, 000 buck and with rifled slugs too.

BTW.......... you won't hurt your gun firing any type of shot through any of those chokes. The one thing you don't want to do is fire slugs thru a tight full choke - that might get ugly.