[kouye]

There's only one think plate/shim that I can see, unless there's one under it.

Edit: Okay, so I replaced the action screw shim with one that is slightly thinner. I can now run a dollar bill under the barrel from the front edge of the rear sight to the front sight. I have the rear band only tight enough to keep it from slipping over the retaining spring. The front band is cinched down to about 5 in/lb.