The animation for the GM6 Lynx where the barrel pulls back to exhaust the used round and rearm from the magazine does not happen on the final shot.
As can be seen in these (real) videos the barrel should always spring back, even if there isn't a round in the magazine, it should at least exhaust the currently used round.
https://www.youtube.com/watch?v=t-Vrvh7qeGA#t=21
https://www.youtube.com/watch?v=NBntnnCFvOk
https://www.youtube.com/watch?v=NFXgxBGcaak