Ruger 10/22 Threaded SS Barrel 18" - heavy, bull barrel, .920 diameter, OAL 18", 416 stainless steel, twist 1:16, CNC Threaded 1/2 x 28 TPI and comes with knurled aluminum thread protector. Threads are centered to bore for reliable accessory use. Weight 3.10 lbs. (No ship to DC)