Here is a page from the S&W Centennial catalog that will help you sort this out. The difference is subtle, but it is there when you know what to look for.....
Here is a page from the S&W Centennial catalog that will help you sort this out. The difference is subtle, but it is there when you know what to look for.....
The S. & W. ".357" Magnum brochure that accompanied Registered Magnum shipments defined the Call front sight as a "disk set into the rear face of a Patridge sight flush with the face".
In actuality I owned a Pre-War .357 Magnum with a Call front sight that is slightly "proud" - pictured in my post #5 above - and have seen many other Call beads that were also slightly "proud". I also owned another Pre-War .357 Magnum with a Call front sight that was in fact flush with the rear face of the Patridge sight - the Patridge sight on that gun had been "smoked" and I didn't even know the Call bead was there until I thoroughly cleaned it.
Below is a page from the S. & W. ".357" Magnum brochure defining several of the available front sights including the Call and McGivern. I believe the bottom line is the Call is a disk (regardless of whether it's flush or proud) and the McGivern is a half sphere.