In the cocking step, what action does the slide perform?

In the cocking step, the slide's primary action is to force the hammer back. This is an important function as it prepares the pistol for firing. When the slide moves to the rear during the cocking process, it compresses the mainspring and positions the hammer in a cocked position, allowing for a subsequent trigger pull to release the hammer and fire the round.

In this context, while other actions like chambering a new cartridge or extracting a spent casing may occur in different sequences of operation, they are not part of the specific cocking step which focuses solely on preparing the hammer. The locking of the barrel is a separate mechanism that ensures the firearm operates safely and efficiently during firing but does not occur directly as part of the cocking action. Thus, the option relating to the hammer being forced back accurately reflects the function of the slide during this phase.