.300 AAC Blackout Upper Assembly - (10.5" Nitride Barrel & 9" Lightweight M-Lok Handguard)



This .300 BLK-chambered 10.5” AR-15 upper is optimized for maximum velocity and accuracy in the most compact package possible. A mil-spec barrel made from 4150 CMV promises reliable performance with light or heavy loads, suppressed or unsuppressed. This barrel features a nitride coating to dramatically increase barrel length while retaining MOA precision. Nitride coatings afford the same benefits as chrome lining, minus the loss of accuracy. An A3 mil-spec upper receiver finishes off this kit with a Full-Auto (M16) bolt carrier group. Ships test-fired with a Lifetime Warranty. 

Barrel Features & Specs:

  • Barrel Length: 10.5″
  • Gas System: Pistol Length
  • Barrel Profile: A2
  • Barrel Steel: 4150 CMV
  • Barrel Finish: Nitride
  • Chrome Lining: None
  • Muzzle Thread: 5/8-24
  • Chamber: 300 Blackout
  • Twist Rate: 1:8
  • Barrel Extension: M4
  • Diameter at Gas Block: .750
  • Gas Block Type: Low-Profile
  • Muzzle Device: A2 Flash Hider

Receiver Features & Specs:

  • Receiver Material: Forged 7075 T6 Aluminum
  • Receiver Type: Flattop M4
  • Handguard Type: 9” Lightweight M-Lok Handguard
  • Bolt Carrier Group Included: Yes
  • Bolt Steel: Carpenter 158 Steel
  • Bolt Carrier Profile: Full-Auto (M16)
  • Charging Handle Included: Yes
No FFL required  Made in the USA  Lifetime Warranty

Shipping Restrictions

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

80-Lower.com only ships within the United States. Federal legislation dictates we cannot ship our products internationally.