Action: Semi Auto - Caliber: .223/5.56 - Capacity: 10 - Finish: Hard Coat Black Anodized - Material: Carbon Steel - Stock: 6 Position CAR Stock - Sights: Adjustable A2 Post / Adjustable Dual Aperture - Twist: 1:9 - Barrel Length: 16 - Overall Length: 32 - 35 - Weight: 6 lb - Gas Block with Integral Picatinny-Style Rail - QD Sling Swivel Attachment Point on Bottom of Gas Block - The M&P15 rifle line is Smith & Wesson's version of the popular semi-automatic AR-15 rifle. These rugged lightweight rifles are built to perform flawlessly under varied conditions.