Not sure my issue is the same? Are you saying that with your gun the piston spring stayed compressed? On mine the spring is not compressed, I can cock it in the normal manner but at the end of the cocking travel nothing catches and it backs off to the bear trap. I can release the bear trap by hold the wedge down with a punch and slowly release the cocking arm back to the normal closed position. The sear just does not engage. I assume I can that the cover off without fear of the spring being released?