I don't like the "slide along the top of the barrel" dovetail chisel that I have. I seem to hit the barrel as often as the chisel. Of course, I'm a klutz, so......
I only chisel the rear sight dovetail, and I do it like Jim Kibler. All the other dovetails are filed with a triangular file, which has the teeth ground off one side.
Use the barrel loop dovetails, which are hidden, as practice for the sight dovetails.
Hope this helps,
Andy