A little more info on the S&W's. That screw may be one of three different designs. Oldest is a standard screw that has been "fitted" to the crane and wil be flat on the end as a result. Never mix this one up with the other round-headed sideplate screw. (They are the same screw but the other one is not fitted) The second design is a female cap screw which contains a spring and insert. It is designed to fit itself to the crane, but the spring and insert are easily lost if you are not very careful (I have only seen a few of these, but they are out there. The latest type is the same cap screw / spring / insert, but the spring and insert are captured, so it appears to be a single unit.

Once the screw is removed, open the cylinder, hold it in place with your thumb and slide the yoke forward toward the muzzle, out and away from the cylinder. (This will not result in binding or scratching the cylinder)