Open the action of the rifle, shotgun or pistol: if inspecting a revolver, remove the cylinder.
Press the clip on the side of the Hoppe's Bore Light to turn it on. The light will stay on as long as pressure is applied to the clip, if you wish to keep the light on, slide the plastic band (supplied with the light) over the clip.
Place the end of the light tube into the weapon's action, pressed up against the end of the barrel and pointed down the bore.
Look down the end of the barrel and visually inspect the condition of the bore.
Turn off and remove the Bore Light.