Description The Stag 15 M4 Upper offers the high quality, durable, military proven M4 design you’ve been looking for. Made to mil-spec standards, this upper satisfies the need for a standard GI carbine. Featuring a 5.56x45mm NATO chamber 16″ 1/7 chrome lined barrel with a thermoplastic handguard and A2 birdcage flash hider. This upper half does not include a BCG or Charging Handle. Action: Semi-Auto Direct Impingement Caliber: 5.56 NATO | .223 Twist Rate: 1/7 Button Rifled Muzzle Device: A2 Flash Hider Barrel: 16″, 4150 Steel, Chrome Lined, Government Profile, Manganese Phosphate Coated Handguard: Thermoplastic with Double Heat Shields Receiver Material: Forged and Mil-Spec 7075 T6 Aluminum with Type 3 Hard Coat Anodizing Bolt Carrier: None Gas System: Carbine Length with A2 Front Post Charging Handle: None Additional information Weight 48 oz Dimensions 28 × 5 × 5 in Barrel Finish Mag Phosphate Barrel Profile Government / SOCOM Cartridge Compatibility 5.56 NATO Barrel Length 16" Gas System Length Carbine Twist Rate 1-7 BCG / Charging Handle Not Included MPN STAG15111101 UPC 810052402291