ProMag Industries Magazine, 223 Remington/556NATO, 40 Rounds, Fits Ruger Mini-14, Steel/Polymer Construction, Black RUG-A46 ProMag magazines are made in the USA and backed by a lifetime guarantee against manufacturer's defects. Magazine springs are precision wound using heat-treated chrome silicon wire and each and every step of the assembly process is checked and double checked in order to maintain the same consistent level of quality.