The M1989A1 is big brother to the original M16A1. It was rechambered to accept the same 7.62mm ammo that the AK series of rifles uses so troops could use captured Soviet ammo. Although assault rifle users greatly preferred the American ammo for its damage capabilities, the military implemented this change in anticipation of front-line ammo shortages. With this arrangement, a soldier could kill an enemy and replenish his supply at the same time.[1]
1 - Weapons in this category do not have a governing skill; melee weapons are distinguished from regular items by damage they deal (3d6 as opposed to 1d6 for items)