Unlike other pump-action shotguns available in Far Cry 2, USAS-12 is a full-automatic shotgun. However, its superier fire rate can be a drawback, as beginners who tend to hold the fire button can empty their magazines very quickly. Besides that, it worths 35 diamonds. It can contain more rounds than any other shotguns available in Far Cry 2. Moreover, shooters can use magazines instead of loading each round into the tube, making the user re-engage faster.
Although USAS-12 can be bought latter part of the game, one can found this when doing a specific buddy-mission in northern area.