The trick to getting the bullet feed to work is to remember that there must be more friction between the buffer/action rod than there is between the bullet feed fingers/bullet feed body.
Check the fit of the buffer on the action rod. The buffer should be tight and not easy to slide up and down the action rod, while the bullet feed fingers should be free to slide back and forth in their track on the bullet feed body.
With only only the bullet feed body and feed fingers assembled together, shake them back and forth like a salt shaker. The fingers should snap from stop to stop without binding at either end.
One can also experiment with the screw that attaches the feed fingers to the bullet feed body. Too tight will obviously cause the fingers to bind, but too loose can allow the fingers to tip and bind also.
Make sure that the dampner does not bind in the attach plate. This usually happens when the action rod is attached at too steep of an angle. Try to mount the bullet feed in such a way as to make the action rod as close to the vertical as possible.
