How does semi-automatic action function?

A semi-automatic action functions by automatically chambering a new round after one has been fired. When the shooter pulls the trigger, it fires a round and then uses the energy from that firing—either through gas operation or recoil—to eject the spent cartridge case and load another round from the magazine into the chamber without the need for the shooter to manually reload. This design allows for a quicker follow-up shot compared to manually operated actions.

The other options do not accurately describe the characteristics of a semi-automatic firearm, as they either refer to manual actions or features that do not apply to semi-automatics. This continuous cycle of firing and reloading makes semi-automatics popular in many shooting sports, hunting scenarios, and self-defense situations.