I gotta agree on the Starr being the easiest, it was designed to be. But my favorite gun, the Rogers and Spencer can be the easiest to swap cylinders on out of the other 3 choices. For one thing, bp NEVER fouls the cylinder pin because of the bushing on the front of the cylinder and with a slight modification, you can line up the cylinder pin retaining screw as fast as fast (see pic). When the lever soldered on the screw is turned counter clockwise, it stops on the projecting pin and you're good to go. The only problem is that if you pull it out too far the entire cylinder pin and loading lever assembly comes out when removing the cylinder...just takes some practice not to do that.