The part of a firearm that loads , fires, and ejects shells or cartridges is called the action.

Quick Scoop

  • The action is the central mechanism that:
    • Loads a cartridge from the magazine into the chamber.
* Fires it by allowing the firing pin or striker to hit the primer.

* Extracts and ejects the empty casing after firing.

What the action includes

In most modern firearms, the action is a group of moving parts working together.

Typical components inside or attached to the action include:

  • Bolt or slide (moves cartridges in and out of the chamber).
  • Firing pin or striker (ignites the primer to fire the round).
  • Extractor and ejector (pull and throw out the spent casing).

Why this terminology matters

Firearm safety courses and exam questions often phrase this exactly as: “Which part of the firearm loads, fires, and ejects shells or cartridges?” and the correct answer is action.

Knowing that “action” is the term helps in understanding manuals, safety training, and legal or technical discussions about firearms.

Answer for your post title:
The part is the action (not the stock, barrel, or trigger).

Information gathered from public forums or data available on the internet and portrayed here.