FN AR15 CHF barrels are meticulously hammer forged, utilizing the same proprietary high grade chrome moly Vanadium steel that is employed in FN's renowned machinegun barrels designed to endure the rigors of sustained fully-automatic fire. Following the forging process, each barrel undergoes magnetic particle testing to ensure its freedom from micro-stresses or imperfections, leading to unwavering consistency and superior quality in every barrel dispatched from the facility. Both the bore and chamber of the barrels are lined with chrome, a measure that bolsters resistance against corrosion and shields against heat erosion. This enhancement significantly extends the barrel's lifespan and contributes to dependable chambering and extraction. The inclusion of M4 style feed ramps and a barrel extension sustains uniform feeding, while the matte black Manganese Phosphate finish effectively counters external corrosion and oxidation.