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Complete Upper Assembly - .300 AAC Blackout (16" Parkerized Barrel & 13.5" M-Lok Handguard)



If you're in the market for a sleek way to convert your AR-15 from either a .223 or a 5.56mm NATO caliber to a .300 AAC blackout one, then you need this upper assembly. Just pull your .223 or 5.56mm upper assembly off your lower assembly and mount this one. Yup, it's that easy. All that'll be left is for your to add backup sights or an optic of your choice. This upper assembly comes with a 16" parkerized barrel with a pistol-length gas system. You also get a 13.5" M-Lok free floating handguard for all your attachment needs, such as grips or tac lights.


Gas System: Pistol-length

Barrel Profile: M4

Barrel Steel: 416R

Barrel Finish: Parkerization

Chrome Lining: No

Muzzle Thread: 5/8x24

Chamber: .300BLK

Twist Rate: 1:8

Barrel Extension: M4

Gas Block Size: .750"

Gas Block Type: Low-profile

Muzzle Device: A2 Flash hider

Receiver Material: Forged 7075 T6

Receiver Type: M4

Handguard Type: 13.5" lightweight M-Lok free float

Bolt Carrier Group Included: Yes

Bolt Steel: 9310 steel, magnetic particle inspected

Bolt Carrier Profile: Full-auto

Charging Handle Included: Yes

Benefits of the 16" Pistol-Length Parkerized AR 15 Upper Assembly:

  • 100% legal to own and ship to your front door
  • Not considered a firearm - no FFL paperwork needed!
  • 4140 steel barrel and Freedom parts kit ensure sub-MOA accuracy
  • Prebuilt upper with gas system removes the guesswork of rifle making

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

We are a national retailer of individual components and not all products depicted on this website are legal in every state. Shipping of various products found on this website are prohibited to some states (such as California, Connecticut, District of Columbia, Hawaii, New Jersey, New York, Rhode Island, and Washington). The information, pictures, text or products presented on this website are not a representation by us, and should not be understood by you, that any product or completed firearm is legal to assemble or own in your state of residence. We encourage each and every builder to perform their own research about the state and federal laws that apply to them. It is your responsibility to understand the law and we encourage you to consult with an attorney or your local ATF representative.