All our uppers are carefully assembled and tested and ready to go out of the box. Every component is chosen to ensure a high quality upper is produced. Every upper is custom built to order and we go the extra mile to ensure the finished product is to your specifications. This 300 Blackout upper starts with an AR-15 MILSPEC 7075 T6 Forged Aluminum receiver, mated to a Ballistic Advantage 9 inch 300 Blackout, Pistol Length Gas System, 1:7 Twist, Govt Profile, QPQ Nitride/Melonite treated barrel. Ballistic Advantage is one of the best barrel manufacturers and they produce high quality, accurate barrels. The Bowden Rail is a free floated system, M-LOK slots on all three sides, full length picatinny rail at the top, lightweight handguard. Barrel Nut is made out of solid steel to ensure a solid mounting system. This configuration has an extended handguard longer than the barrel, with a flash can to provide a sleek look and maximum sight radius. Bolt Carrier Group and Charging Handle is OPTIONAL. We offer TWO choices of BCG. 1) a NITRIDE BCG, M16 Profile, Properly Staked Gas Key, MP Tested, 8620 Carrier, 9310 Bolt. OR 2) a NICKEL BORON BCG, M16 Profile, Properly Staked Gas Key, MP Tested, 8620 Carrier, 9310 Bolt. Standard Charging Handle included in options. We can also UPGRADE the GAS BLOCK to an Adjustable Gas Block. Great option if you are using a suppressor or just want to fine tune your system. Also an OPTION is COLOR. We can change the receiver and handguard to MAGPUL FDE (FLAT DARK EARTH) COLOR (see pictures). SPECIFICATIONS UPPER RECEIVER: AR-15 Mil-Spec Machined out of 7075-T6 Forged Aluminum, M4 Feed Ramps, Type III Hardcoat Anodized Black with Forward Assist and Ejection Port Cover Installed BARREL: 9 inch, 300 Blackout Caliber, 4150 Chrome Moly Vanadium Steel, 1:7 Twist, Govt Profile, QPQ Nitride/Melonite Treated - made by Ballistic Advantage HANDGUARD: 10 inch M-LOK Free Floated, Machined out of 6061 T6 Aluminum - made by Bowden Tactical GAS SYSTEM: Pistol Length, Direct Impingement, Stainless Steel Tube GAS BLOCK: Low Profile Gas Block, Machined out of 4140 Steel MUZZLE DEVICE: Standard 5/8-24 Slimline Flash Can 100% MADE IN THE USA OPTIONAL: ADD a Nitride OR Nickel Boron M16 Profile BCG; and Standard Charging Handle OPTIONAL: UPGRADE GAS BLOCK to an Adjustable Gas Block OPTIONAL: COLOR Change to a Magpul FDE Colored Receiver and 10 inch M-LOK Magpul FDE Colored Handguard