What part of a firearm is considered the 'heart'?

The action of a firearm is often referred to as its 'heart' because it encompasses the mechanisms that load, fire, and eject cartridges. Essentially, the action is the core component that allows the shooter to operate the firearm effectively. It includes parts such as the bolt, firing pin, and various springs that work together to function when the trigger is pulled. Understanding the importance of the action is crucial for safe handling and operation, as it is the main area where the critical interaction between the user and the firearm occurs.

In contrast, the barrel is important for directing the projectile and affecting accuracy, but it does not contain the critical mechanical workings of the firearm. The stock is mainly for stabilization and comfort during shooting and does not engage in the firing process. The trigger, while essential for firing the gun, is just one part of the action and doesn't encompass the full mechanism that operates the firearm. The action’s role in the overall functioning of the firearm solidifies its designation as the 'heart.'