The DR920P’s patent pending compensator includes a locking key to ensure return to zero and proper front sight alignment. It is a novel design feature that is crucial to the accuracy of the system. Here we break down the gun and take a look at the function of this component.
Technical Tuesday – DR920P Locking Key Explained

How often are we supposed to clean the DR920P’s compensator?
I like to clean mine after every range trip with some bore solvent and a plastic bristle brush.