The ballastics advantage 11.3" 5.56 ba hanson carbine length ar 15 performance series barrel with lo pro is machined from 4150 chrome moly vanadium steel with a qpq corrosion resistant finish.The performance series barrels feature a nickel boron coated m4 feed ramp extension.Hanson series barrels feature our proprietary ba hanson profile , carbine gas system length, 1.00" gas block seat for.625" low profile gas blocks only and include a pinned lo-pro gas block.Hanson barrels are not designed to work with aftermarket piston kits.Caliber Or Gauge: 223 Remington/5.56 NATOLength: 11.30"Model: AR BarrelTwist: 1:7"Sights: NoneFinish: QPQ Corrosion ResistantType: RifleBarrel Type: BA Hanson Carbine LengthBarrel Features: Low Profile