ProMag Industries Magazine, Drum, 30 Carbine, 50 Rounds, Fits M1 Carbine, Polymer Construction, Black DRM-A103 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.