Limb is probably just a tad lose in the pocket. Two tiny felt pads about the diameter of a pencil eraser on each side of the top or bottom of the limb near the butt. Small rubber pads would also work. Or you might find some nylon drawer stop pads and cut them down to size. You'll only need a sixteenth of an inch or so, maybe less. For that matter, a couple thicknesses of duct tape might do it. Good luck.
Oops. Didn't see the other thread on this topic.