Abstract: Embodiments are directed toward a pivot pin for a coupling an upper receiver of a firearm to a lower receiver of the firearm. In some embodiments, the pivot pin includes a head and a shaft that extends from the head. In some embodiments, the shaft defines a detent-retention channel and an installation aperture opposite the channel from the head. In some embodiments, the channel is configured to receive a detent and to enable the pivot pin to slide between a locked configuration and an unlocked configuration. In some embodiments, the installation aperture is configured to receive a tool that extends through the shaft, thereby urging the detent into a detent recess in the lower receiver while the shaft covers the detent recess in the lower receiver. Accordingly, the installation aperture facilitates reducing the likelihood that the detent escapes from the detent recess during installation of the pivot pin.