I find it interesting that we are having a conversation about cylinder choke, and no one has thus far mentioned that few are the shtoguns that have a true .729 bore, something particularly true off the continent, were a tighter bore was favored for many years.
A 12 gauge shotgun with a .719 bore, and a .719 choke, or no choke in the end, is going to pattern differently than a shotgun with a .729 bore and no choke. Even though the average bloke would call either gun "cylinder" choked, or, more correctly, no choke.

Best,
Ted