ProMag Industries Drum Magazine, 22LR, 55 Rounds, Fits Ruger 10/22, Polymer, Translucent Smoke RUG-A28 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.