When you open the action, an ejector barrel will click as the ejector springs out, an extractor makes no noise to speak of. An ejector can be pushed back into the underlug against the spring pressure when the action is open, an extractor can't unless you remove the barrel from the frame. You can tell the difference if you can see bottom of the underlug, but not without removing the barrel from the frame. Underlug pics are in the FAQs.
Tim