I just received a shipment of uppers and barrels from SIONICS. This company is based out of Tucson, Arizona and is focused on the AR-platform. Their chrome lined barrels are 11595E 41V50 Steel, NATO Chamber, and X-Ray and MP Inspected! Their Bolt and Bolt Carriers are 100% HPT & MPI, Shot peened and the carrier is Nickle/PTFE plated. [ame="http://youtu.be/4kMPTc4ZkgU"]http://youtu.be/4kMPTc4ZkgU[/ame] What can be considered as premium components can all be found in this SIONICS Patrol Rifle I Upper Assembly for $684! http://www.rogtac.com/sionics-patrol-i-upper.html Patrol Rifle I Upper - Black Configuration: AR15 Style Carbine, 5.56mm NATO Upper Receiver: 7075 M4 Barrel: 16” Medium Weight, 41V50, NATO Chamber, 1:8, Chrome Lined, Air-Gauged, Radiograph and MP Inspected Gas System: Mid-Length, Direct-Impingement Bolt Carrier Group: Nickel PTFE M16 Carrier, Carpenter 158 Steel, HPT/MPI, Shot peened, staked gas key Charging Handle: Mil-spec charging handle included Front Sight: F-Marked Front Sight Base Muzzle Device: A2 Flash Suppressor Hand Guard: Magpul MOE All upper receiver assemblies are test fired by SIONICS. * Rear sight is not included. Barrel Details 11595E 41V50 Steel 5.56mm NATO Chamber Hard Chrome Lining X-Ray and MP Inspected SIONICS barrel blanks are made from MIL-B-11595E Certified (41V50 CMV) Steel. They are chambered and rifled to best suit the purpose of each particular barrel. The gas ports are properly sized. The barrels are finished with hard chrome bores and chambers. After completing a Quality Control inspection of the raw blanks, each barrel is checked for proper headspacing, profile dimensions, gas port size and location. Muzzle Crowns are inspected under magnification. All SIONICS barrels receive a durable Manganese-Phosphate outer finish. SIONICS barrels are 100% X-Ray and Magnetic Particle inspected by an independent ANSI Certified facility. Feed ramps and chambers are lightly polished and if required, front sight bases are installed in a custom alignment fixture using hardened and tapered cross pins. Every barrel is test fired to ensure reliability, function and accuracy. Any barrel that does not pass every test and inspection is rejected. Bolt & Bolt Carrier Details 100% HPT & MPI Shot Peened Heavy Extractor Spring Black Insert and O-Ring Nickel PTFE Carrier SIONICS bolts are made by a current defense contractor from Carpenter 158® Steel. The bolts are 100% high pressure tested and magnetic particle inspected. Each bolt is shot peened and comes with a heavy extractor spring, black spring insert and O-Ring. SIONICS bolt carriers are also manufactured by a current defense contractor. Only M16 bolt carriers are used. The keys are checked for a flat fit before being installed and the bolts are side staked. Each carrier assembly is treated with a durable Nickel/PTFE plating which creates a permanently lubricious surface which eliminates the need for grease, oil or any wet lubrication.