Lead & Steel LS9MM8.3-28 AR9 Barrel 8.30" Nitride 1/2"x28. Lead & Steel AR-9 barrel made from 4150 Chrome Moly Vanadium steel and finished with a QPQ nitride treatment. This 8.3-inch barrel is threaded 1/2x28 and ready for 9mm muzzle devices and suppressors, making it an excellent choice for AR-9 pistols or compact PCC builds. Not available to ship to California, Illinois, Massachusetts, or Washington. SPECS include Caliber/Gauge: 9mm; Barrel Length: 8.3; Barrel Twist: 1:10; Barrel Bore Type: Rifled; Barrel Finish: Nitride; Threaded Barrel: Yes; Weight: 1.00 Lbs; UPC: 7427053012546; Mfg. Part Number: LS9MM8.3-28; Country of Manufacture: No; Firearm Fit: AR-15; Threading: 1/2x28.