300 Blackout AR 15 Rifle Kit (16" Parkerized Heavy Barrel & 15" M-Lok Handguard) w/ 80% Lower (1:8 Twist)

(You save $132.50 )


Please note: We strive to provide the most accurate photographs of our product wherever possible. Due to availability limitations and supply chain constraints, slight variations of the handguard of this upper assembly may occur in the aesthetics of the skeletonizations in between the M-Lok sections.

For the longrange shooter who demands a do-it-all AR with a .30-cal. This 300 Blackout build kit provides a lightweight rifle that can shoot suppressed or un-suppressed with supers and subs all day (and night, for the hogs). With a 16" barrel forged from 4150 CMV with a 1:8 twist providing optimal velocity and stability for all grains and loads, this rifle kit yields MOA accuracy in any configuration.

300 BLK Rifle Kit Specs:

Gas System: Pistol-length
Barrel Profile: Heavy
Barrel Steel: 4150 CMV
Barrel Finish: Parkerization
Chrome Lining: No
Muzzle Thread: 5/8x24
Chamber: .300 AAC Blackout
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 w/ Feedramps
Handguard Type: 15” M-Lok
Bolt Carrier Group Included: Yes
Bolt Steel: 9310 steel, MPI/HPT
Bolt Carrier Profile: Full-auto
Charging Handle Included: Yes

Benefits of the 16” Carbine-Length Black-Barreled AR 15 Rifle Kit:

  • 100% legal to own and ship to your front door
  • Not considered a firearm – no FFL paperwork needed!
  • 4150 Chrome moly vanadium steel barrel ensures sub-MOA accuracy
  • Prebuilt upper with gas system removes the guesswork of rifle making
  • Includes bolt carrier group, free-floated M-Lok handguard and lower parts kit

Add'l Kit Details:

Barrel: 16″; Carbine-length gas; Parkerized finish; Chambered in .300BLK; 1:8 twist rate; .750″ low-profile gas block; 15” M-Lok handguard; A2 “birdcage” flash hider; Made from mil-spec 4150 Chromoly Vanadium.

Upper Receiver Assembly: Forged from 7075-T6 aluminum; Hard-coat anodized in black for durability; M4 feed ramps; Made in the USA.

Bolt Carrier Group: M-16 / Full-Auto bolt carrier group; Made from 9130 steel; High-pressure tested (HPT) with live proof round; Quality inspected after proof with magnetic particle inspection (MPI).

80% Lower Receiver: Choose to receive a forged or billet Fire/Safe 80% lower receiver. Our lower receivers are anodized to match the upper receiver perfectly. They come ready for machining the trigger pocket and drilling of the safety selector and trigger pin holes. Pair with an 80% jig (AR-15).

AR-15 Lower Parts Kit: Includes all lower receiver parts needed to assemble the lower receiver. Includes pistol grip, safety selector, and complete fire control group. All components in the LPK are mil-spec in material, fit, and finish.

Lower Assembly: Comes with complete buffer tube assembly. Mil-spec tube and buttstock threads and diameters. Includes Carbine (3.0-ounce) buffer, spring, six-position buffer tube (forged), latch plate, castle nut, and M4-type butt stock based on original Colt design.

Charging Handle: Standard/mil-spec; Made from 6061-T6 aluminum.

Please note: This build kit requires that the builder complete the 80% lower receiver (instructions here) but that’s the rewarding part of the experience! (It's the only way to build your own AR-15 without the need of an FFL transfer or serialization).

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.

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, 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.