A firing pin with a flat, four-sided shape can be found in various firearms. This specific geometric configuration influences the impact on the primer, affecting ignition reliability and performance. For instance, this shape distributes force differently than a round or elliptical pin, influencing the firing process.
The design contributes to consistent primer strikes due to its larger surface area compared to alternative shapes. This characteristic is crucial for reliable ignition, especially in adverse conditions or with varying ammunition types. Historically, this shape has been favored in certain firearm designs due to its ease of manufacture and robust performance. Its evolution is tied to the broader development of firearm mechanisms and the ongoing pursuit of improved reliability and efficiency.