Ammunition Storage Components Ammunition Storage Components, Magazine, 223 Remington/556NATO, 5 Rounds, Fits AR Rifles, Stainless, Black Follower, Black 5-223-SS-BM-B-ASC Designed for the AR-15 Platform" Ammunition Storage Components (ASC) builds some of the best magazines available on the market today. ASC magazines are built with the highest quality components to ensure reliable functioning and increased longevity. This is why they have become the approved supplier for many of the most well-known firearms manufacturers in the nation.