A gun light is a dual-purpose system. It is fixed parallel to the axis of the gun barrel, so it also act as an aiming aid. The disadvantage is that it's unidirectional.



The field light the USCMC uses projects out in multiple angles and down. It does not serve as a weapon sight, but rather to illuminate the territory. In the event the light would compromise them, they can shut it off and use infrared imaging. Riflemen (Marines carrying the M-41A standard issue pulse rifle) have the IR in their helmets. Machine gunners (Marines carrying the M56 smartgun...the big gun) have IR imaging in their smartgun sights.