When it stops I can rack the handle and get another few shots off at a good rate of fire. My can isn't new but i can still feel some liquid propane sloshing around in there.
I tried to see if the BCG was not engaging the auto-sear by taking the mag out, racking the handle, switching to auto, pulling the trigger and then racking the handle. It succedes in dropping the hammer every time the bolt returns to the forward position :-S