Abstract: A flashlight for bore sighting a long barreled shotgun or rifle including a cartridge case with an ejector rim and a primer opening in the base, and a sidewall defining an open front end; a battery and a light bulb within the case; a switch pin slidable in the primer opening to complete the circuit for illuminating the bulb, a spring normally urging the switch pin outwardly and a metallic bulb holder adjacent the front of the case; in a shotshell case, the bulb holder having a frame shank extending along the battery and to the base thereof, the shank having an apertured flange at the base of the battery, spaced from the battery by an insulator and the hole in the flange aligned with the switch pin.