ProMag Industries ProMag, Magazine, 762X39, 30 Rounds, Fits AR15/AR47, Steel, Blued Finish COL-A20 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.