Which part of the firearm is most commonly handled during aiming and firing?

The stock is the part of the firearm that is most commonly handled during aiming and firing. It provides the shooter with a stable and comfortable grip, allowing for better control and accuracy when aiming at a target. The stock is designed to rest against the shoulder, which helps absorb the recoil of the firearm and facilitates a more steady aim.

While other parts of the firearm have important functions, they are not typically manipulated in the same way during the firing process. For instance, the trigger guard helps protect the trigger from accidental discharge but is not directly handled during aiming. The barrel is crucial for directing the projectile, yet it is not something that shooters grasp while aiming. The action is involved in the loading and firing sequence but does not lend itself to the handling needed for aiming. Thus, the stock's role in providing support and stability makes it the primary part handled by shooters while they aim and fire.