ASC manufactures an American classic that transcends the industry standard with the use of cutting edge robotic manufacturing technology and ASC's commitment to construct magazines with only the highest quality materials. These lightweight aluminum magazines are manufactured 100 percent start to finish in the USA using 6061 T0 grade aluminum heat treated to a condition of T6 and hard coat anodized per MIL-A-8625 Type III class I for ultimate longevity.AR-15 Platforms chambered in .223 and 5.56 NATO