Faxon Match Series 16" Gunner .338 ARC Pistol-Length 416-R Stainless AR-15 Barrel. Machined from premium 416-R stainless steel and button-rifled, this 16" .338 ARC barrel features an 11 target crown, 1:8 twist rate, 5/8" 24 muzzle threads, and a .750" gas block journal. The Gunner profile shifts weight rearward for better balance and reduced shooter fatigue ideal for long days of shooting, training, or hunting. Inside and outside finishes are salt-bath nitride for corrosion resistance and durability. Barrel extension is M4 and the barrel is magnetic-particle inspected for quality assurance. Features Barrel Material: 416-R Stainless Steel Barrel Type: Button Rifled Caliber: .338 ARC Twist Rate: 1:8 Length: 16" Profile: Gunner (rearward balance to reduce fatigue) Gas System: Pistol-length Inside Finish: Salt Bath Nitride Outside Finish: Salt Bath Nitride Muzzle Thread: 5/8" 24 TPI Gas Block Diameter (journal): .750" Gas Block Journal Length: 1.9" Barrel Extension: M4 Weight: 1.40 lbs Inspection: Magnetic Particle Inspected Muzzle: 11 target crown Manufacturer: Faxon Firearms Product Specifications Barrel Length: 16" Barrel Thread Pitch: 5/8" 24 TPI Brand: Faxon Firearms Caliber: .338 ARC Finish / Color: Salt Bath Nitride (black) Firearm Type: Rifle (AR-15 platform) Material: 416-R Stainless Steel Models Fit: AR-15