Highly recommend calling CZ-USA. The manuals for CZ shotguns stink (IMO). They talked me through how it is supposed to work, to make sure function was correct. In the end, because of what I have the 712 for (sporting clays), I just feed one in the chamber, close the bolt, and then manually put one in the tube. I've never had issues with it not feeding that second round from the tube while shooting.