Armalite generation II AR-10 magazines have proven to be a stunning success. It is constructed of aluminum with a stainless steel spring and hardcoat anodized finish.Armalite generation II AR-10 magazines in 20 round capacity have proven to be a stunning success. Building on that success, Armalite now offers a full range of these fine magazines from 5 to 25 round capacity, covering all uses from big game hunting to hard military or Law Enforcement use.