A misfire is primarily caused by what?

The primary cause of a misfire is a failure of the primer to ignite. In the function of a firearm, the primer serves a crucial role by detonating upon impact when struck by the firing pin, which in turn ignites the gunpowder and propels the bullet. If the primer fails—whether it be due to manufacturing defects, moisture, or it being improperly seated in the cartridge—the result is a misfire, where the firearm does not discharge as intended.

Although other factors such as bad gunpowder, improper handling, or damaged casing can contribute to overall firearm malfunctions or affect the reliability of ammunition, they do not directly account for the specific instance of a misfire as the primer's ignition is the pivotal event that initiates the firing sequence. Therefore, the failure of the primer to ignite is the most accurate explanation for a misfire situation.