Navy jets have been dropping 500 lb. bombs in Iraq on ISIL positions in northern Iraq. The 500 lb. bomb is one of the smallest and one of the most common air-dropped weapons in the world. Although the nominal weight is 500 lbs., its actual weight varies considerably depending on its configuration, from 510 lbs. to 570 lbs. It comes with a streamlined steel casing containing 192 lbs. of Tritonal high explosive. The bombs being used in Iraq are laser-guided for precision.