Sons Of Liberty Gun Works M4-89 5.56X45 NATO 13.7'' BBL 13'' M89 RAIL W/NOX BRAKE M489UPPER-13.7-556-B

Sons Of Liberty Gun Works M4-89 5.56x45 NATO 13.7'' Barrel Upper with 13'' M89 Rail & NOX Brake - M489UPPER-13.7-556-B Experience unmatched reliability and precision with the Sons Of Liberty Gun Works (SOLGW) M4-89 Upper Receiver – model M489UPPER-13.7-556-B. Chambered in 5.56x45 NATO, this combat-ready 13.7-inch barrel AR-15 upper features a premium 13'' M89 Rail and NOX Muzzle Brake for superior control and modularity. Built for duty, range domination, or home defense, the SOLGW M4-89 is the ultimate upgrade for serious shooters seeking SOLGW uppers. Premium Features of the SOLGW M4-89 Upper 13.7'' CMV 4150 Barrel: Government-profile, nitride-treated for extreme durability, accuracy, and heat resistance in 5.56 NATO. 13'' M89 Rail System: Free-float M-LOK handguard for endless accessory mounting – lights, grips, optics, and more. NOX Muzzle Brake: Advanced flash-hider and recoil reducer minimizes muzzle rise for faster follow-ups. Full-Auto Rated BCG: SOLGW proprietary bolt carrier group with enhanced extractor and ejector for flawless cycling. Mil-Spec Charging Handle: Ambidextrous compatibility for smooth operation under stress. Pinned & Welded Gas Block: Low-profile design ensures reliability without forward assist interference. 7075-T6 Forged Upper: Hardcoat anodized for corrosion resistance and lightweight strength. Why the Sons Of Liberty M4-89 Upper Excels Sons Of Liberty Gun Works sets the standard for AR-15 uppers with battle-tested designs inspired by military specs. The M4-89 13.7'' 5.56 upper delivers pinpoint accuracy out to 500+ yards, suppressed or unsuppressed. "This thing runs like a dream – zero malfunctions after 5,000 rounds!" raves a SOLGW user. Perfect for building custom AR-15 rifles, SBRs, or completing your lower, it's optimized for mid-length gas system efficiency. Top search terms like SOLGW M4-89, 13.7 inch 5.56 upper, M89 rail upper, and NOX brake AR upper lead straight to this beast. Proudly made in the USA with a lifetime warranty – because SOLGW builds uppers that last. Compatibility & Detailed Specifications SpecificationDetails Model NumberM489UPPER-13.7-556-B Caliber5.56x45 NATO / .223 Remington Barrel Length13.7 inches Rail Length13'' M89 M-LOK Muzzle DeviceNOX Brake Gas SystemMid-Length Barrel Material4150 CMV Nitride WeightApprox. 3.2 lbs (complete upper) CompatibilityMil-Spec AR-15 Lowers What Shooters Are Saying "SOLGW M4-89 is the best 13.7 5.56 upper money can buy. Laser accurate and tough as nails." – Mike R., NC "M89 rail is game-changing for my build. NOX brake tames the recoil perfectly!" – Tactical Tim, AZ Build Your Dream AR-15 Today Don't settle for lesser uppers – the Sons Of Liberty Gun Works M489UPPER-13.7-556-B is engineered for excellence. Ideal for AR builders, 3-gun competitors, or patriots defending freedom. Pair it with your favorite lower, optic, and suppressor for a setup that outperforms the competition. Limited stock – secure your M4-89 upper now! The End