"Hard Locked Casing" is when an empty casing fails to eject or eject and the slide appear like it has failed to go home, but in fact it will not move whether you smack it forward or try to lock it to the rear; it is simply stuck in animation. What happens is the brass swells to an extent where it gets stuck in the chamber. Mortaring requires u grab the slide with your reaction hand in a "c" clamp manner. Then with your weapon hand, as if you were drawing the weapon, do that as hard as u can against the back of the frame until the malf is clear. Warning: gun may fly out of your reaction hand. If this malf occurs pls make sure you take all necessary safety precautions prior to clearing. If possible remove magazine from weapon. In some cases the mag will not fall. Hope this helps!