I have no use for cylinder choke. Years ago, when I discovered handloading and patterning and went at it with a vengeance, I decided the best way to improve my O/U was to open the first barrel to true cylinder. Subsequent hunting and patterning convinced me it was ruined. I got rid of the gun and vowed to never flirt with cylinder choke again. These days, the most open choke in any of my shotguns is .005 in the first barrel of my 20ga bird gun. It dispatches woodcock cleanly at 15 yds without mangling them. I miss them occasionally, but I've never been tempted to "spray and pray" again.