Drive your .300 BLK to peak precision performance.
The .300 Blackout isn’t just for close quarters. This 16" upper features a 416R stainless, fluted, and Melonite-treated barrel built for stability and precision, extending the caliber’s practical performance downrange.
This barreled upper comes ready to install, while the lower build kit provides all components necessary to finish your stripped AR-15 lower receiver.
What’s Included
This is not a firearm. It includes an assembled upper receiver, bolt carrier group, and a charging handle.
300 BLK AR-15 Rifle Kit Specs
Barreled uppers are assembled in-house before shipment.
Barrel
- Chamber: .300 AAC Blackout
- Contour: Heavy, Straight Flutes
- Length: 16”
- Twist Rate: 1:8
- Gas System: Carbine
- Gas Block: 0.750”
- Muzzle Threads: 5/8x24
- Material: 416R Stainless
- Finish: Nitride
- Lining: Stainless
- Extension: M4
- Muzzle: Twisted Flash Hider
Handguard
- Attachment System: 12" M-LOK w/ Split Top Rail
- Finish: Type III Hardcoat Anodized (Mil-Spec)
- Top Rail: M1913 Picatinny
- Material: Billet 6061-T6 Aluminum
- Attachment: Barrel Nut
Upper Receiver
- Profile: M4 Flattop
- Material: Forged 7075-T6 Aluminum
- Finish: Type III Hardcoat Anodized (Mil-Spec)
Bolt Carrier Group
- Profile: M16/Full-Auto
- Steel: 9310 Tool, HPT/MPI-tested
- Exterior: Black Nitride
- Interior: Black Nitride
- Gas Key: Staked
- Charging Handle: Included
Lower Receiver Parts
- Buffer System: Mil-spec, Carbine
- Buttstock: Mil-spec, M4-type
- Parts Kit: Mil-spec, single-stage
Lower receiver not included.
WARNING: Handling firearms parts and accessories can expose you to lead and other petroleum products known to the State of California to cause cancer and reproductive harm. For more information go to: www.P65Warnings.ca.gov
Shipping of various parts and/or accessories are prohibited to states and locales (ie New Jersey, California, New York, etc…) with restrictions against certain parts and/or accessories or "assault weapons" (i.e. states with high-capacity magazine restrictions, manufacturing of semi-automatic weapons, etc..). It is your responsibility to be aware of your local firearms laws before purchasing from our website or machining a firearm. We try our best to keep our shipping page current, but laws change daily.
GunBuilders.com only ships within the United States. Federal legislation dictates we cannot ship our products internationally.
