LWRC Individual Carbine SPR Complete Upper Features The LWRC Individual Carbine SPR Complete Upper is built around a 16 inch cold hammer forged barrel chambered in 5.56 NATO with a 1:7 twist rate giving it the stability to handle a wide range of bullet weights accurately. LWRC s signature spiral fluting cuts weight from the barrel while its Nicorr finish adds corrosion resistance and heat tolerance beyond a standard coating. An adjustable short stroke gas piston system keeps fouling out of the action which means a cleaner bolt carrier group and fewer malfunctions over extended use compared to a direct impingement design. A 4 prong flash hider at the muzzle helps control signature during firing. This complete upper ships with everything needed to get it running including an LWRC bolt carrier group ambidextrous charging handle properly matched buffer and spring and folding back up iron sights. The modular free float handguard uses LWRC s proprietary accessory mounting system and its top half can be removed easily to access and adjust the gas block without disassembling the whole rail. The forged aluminum upper receiver arrives fully assembled so builders can drop it directly onto any Mil-Spec lower receiver. LWRC designs manufactures and finishes every component in Cambridge Maryland and this IC SPR Complete Upper is available for sale at GrabAGun for anyone ready to upgrade their AR-15 build. LWRC Individual Carbine SPR Complete Upper Specifications Manufacturer: LWRC Model: Individual Carbine SPR Complete Upper Caliber: 5.56 Barrel Length: 16 Twist Rate: 1:7 Color: Black Barrel Description: Cold Hammer Forged Spiral Fluted Nicorr Finished Gas System: Adjustable Short Stroke Piston Includes: Bolt Carrier Group Ambidextrous Charging Handle Buffer and Spring Folding BUIS Available At: GrabAGun