The barrel is professionally CNC threaded 1/2-28 TPI on centers for easy screw-on suppressor or 9MM muzzle accessory mounting. REMEMBER this is a 9mm barrel . Do not install a smaller caliber flash hider or other accessory.
The barrels are 10.25" and made from 4140 chrome moly steel, button rifled, 1:10 twist and are military black phosphate finished. The chambers are machined identically to the original SMG military profile for reliable feeding and chambering.