So looking at the info I have, a Remington barrel is around .727 and the .018 constriction places it around .710. In my experience .720 is the ideal option if you wanted one choke for all Duck loads at ethical Flooded Timber ranges——30 - 35 yards and in. Some of us are on the run all the time and we do not reload. We need a decent all around choke that works with a variety of factory loads so if we forget to bring shells, we can run in store and get what they have off the shelf. I hunt flooded timber exclusively. Switching chokes while standing in waist deep water is a receipe for losing a choke tube.