Which of the following describes the action of removing a spent cartridge case?

The action of removing a spent cartridge case is properly described as ejecting. When a firearm cycles, after firing a round, the spent cartridge case must be removed from the chamber to make way for a fresh round. Ejecting refers specifically to the process of forcefully expelling this spent cartridge case from the firearm, allowing it to fall away from the weapon.

In firearms operation, extracting precedes ejecting; extracting involves pulling the spent cartridge case out of the chamber, while ejecting is the final step where the case is pushed out and away from the firearm. Chambering refers to the act of loading a fresh round into the chamber, which occurs after ejection. Unlocking pertains to disengaging the locking mechanism that keeps the bolt in place, allowing for extraction and ejection to occur. Therefore, the term ejecting is the most accurate description of the action in question.