Pedantic again. The bottom illiustration is not quite correct in reality because you could not have a breech block forward and fully locked and an unfired round in the chamber. In the same was that you could not have the change lever set at SAFE in this mode. Your finger simply could not operate it from A or R to SAFE in the time taken for the breech block to move from the sear to LOCK.
I'd be interested to see how you interpret the cam operation of the barrel nut plunger, its spring and the mag opening cover plunger
But VERY good