What is the purpose of the extractor in the bolt and bolt carrier assembly?

The purpose of the extractor in the bolt and bolt carrier assembly is to withdraw the cartridge case from the chamber. When a round is fired and the bullet is propelled out of the barrel, the pressure generated within the chamber expands the brass casing. The extractor is a small claw-like mechanism that engages the rim of the spent cartridge case as the bolt begins to move rearward during the cycling process. This engagement allows the extractor to pull the empty case out of the chamber, ensuring the firearm can cycle effectively and prepare for the next round to be chambered.

This function is critical for the reliable operation of the automatic or semi-automatic firing mechanism, as it prevents spent cases from becoming stuck in the chamber and contributing to malfunctions. The other choices refer to functions that do not accurately represent the role of the extractor in the firing cycle.