ASC Stainless Steel magazines are an improvement on a classic, with the highest levels of durability and increased longevity, simply the best in the industry! ASC magazines are manufactured 100% start to finish in the USA using .020" gauge 410 Stainless Steel Alloy and heat treated for superior strength and lasting endurance. The magazines are chemically treated for corrosion resistance. 410 Series Stainless Steel Body, Heat Treated Chrome Silicon Springs Enhanced Anti-tilt Polymer Followers with PTFE 300 Series SS Floor plate with Black Oxide Coating for Corrosion Resistance Mfg: Asc