LBE Unlimited AR-15 Ready Build Kit Complete Upper Features The LBE Unlimited AR-15 Ready Build Kit Complete Upper is built around a 7.5 cold hammer forged barrel in 5.56 NATO a manufacturing process that improves barrel longevity and heat resistance over button rifled barrels. The barrel wears a melonite finish for added corrosion resistance and a slicker bore surface both of which extend service life under repeated firing. A pistol length gas system paired with a low profile gas block and pinned gas tube is purpose built for the short barrel timing gas pressure correctly for reliable cycling in a compact footprint. This combination makes the kit a natural fit for an AR pistol build or an SBR project where a longer gas system would not work. The upper receiver arrives with the dust cover and forward assist already installed cutting down on the small-parts fitting that otherwise slows down a build. Inside an NiB coated M16 style bolt carrier group provides a hard low friction surface that resists carbon buildup and eases cleaning after extended range sessions. A standard charging handle and an A2 flash hider with crush washer complete the package giving the builder everything needed above the barrel nut in one purchase. High quality components and precise manufacturing make LBE Unlimited parts a dependable choice for builders assembling or upgrading an AR-15 for sale at GrabAGun. LBE Unlimited AR-15 Ready Build Kit Complete Upper Specifications Manufacturer: LBE Unlimited Model: Ready Build Kit Type: Complete Upper Receiver Caliber: 5.56 NATO / .223 Rem Compatible Hosts: AR-15 Barrel Length: 7.5 Barrel Type: Cold Hammer Forged Barrel Finish: Melonite Gas System: Pistol Length Low Profile Gas Block Bolt Carrier Group: M16 Style NiB Coated Charging Handle: Standard Muzzle Device: A2 Flash Hider w/ Crush Washer Color: Black Available At: GrabAGun