There is another thread where the shape is discussed, but it can be discussed here again. The recess would prolly be wide enough to allow the bands to come back to size. Then they would be exposed at the end, since tha barrel has a taper too. So from the side you would see 12 or so inches of the bands from the muzzle back. (the 12" is just me guessing).
More POV's can be found here:
http://forums.deeperblue.net/spearo-...gun-shape.html