300 Blackout Ultimate AR 15 Rifle Kit (16" Nitride Barrel & Fixed Front Sight) w/ 80% Lower



How can you get an AR-15 with an appearance reminiscent of the old-school CAR-15 and M4? You come to us. How do you get it chambered in .300 AAC blackout, the AR round whose popularity is growing in leaps and bounds? You come to us. How do you get this AR in a kit that you build yourself starting from just an 80% lower receiver? Yep, still us. And how do you get it without breaking your bank? You already know the answer.

At just under a thousand bucks (with the "no lower" option), this AR-15 brings you the same solid performance you've come to expect from us, with the added benefit of being chambered for .300BLK, which is an excellent caliber for hunting and close quarters-type engagements like defending your home. Plus, it's decked out with features. And the best part is, it's completely 100% legal to ship straight to your front door, no FFL transfer or paperwork needed. Nothing in this kit is considered a firearm by any state or federal law. So what's stoppin' ya?


  • Gas System: Carbine-length
  • Barrel Profile: Government
  • Barrel Steel: Chrome moly vanadium
  • Barrel Finish: Black nitride
  • Chrome Lining: No
  • Muzzle Thread: 5/8x24
  • Chamber: .300 AAC Blackout
  • Twist Rate: 1:7
  • 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: CAR-style fixed
  • Bolt Carrier Group Included: Yes
  • Bolt Steel: 9310 steel, magnetic particle inspected
  • Bolt Carrier Profile: Full-auto
  • Charging Handle Included: Yes
  • Overall Length: 24.5″

Premium Accessories:

  • Magpul MBUS Rear Flip-up Sight
  • Mil-Spec Buffer Tube and Stock Kit
  • Tactical Rifle Sling (black)
  • Rugged Tactical Rifle Case (with customizable foam inserts)

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!
  • Chrome moly vanadium steel barrel and Freedom parts kit ensure 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

AR 15 Rifle Kit Details (Expanded):

Barrel: 16″ carbine-length with black nitride finish, chambered in .300BLK, 1:7 twist rate, .750″ low-profile gas block, CAR-style/M4-style fixed handguard, with an A2 “birdcage” flash hider.

Upper Receiver Assembly: Forged from 7075 T6 aluminum, hard-coat anodized in black for durability, features M4 feed ramps, and are made in the USA.

Bolt Carrier Group: The bolt carrier is made from 9310 steel and has a staked gas key and black nitride finish. The bolt itself comes complete with an extractor spring and O-ring insert. It accepts .223 Wylde, 5.56mm, and .300BLK calibers (though you should NEVER attempt to use a caliber for which your rifle is not chambered), and is magnetic particle inspected.

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. and they come ready for machining of the trigger pocket and drilling of the safety selector and trigger pin holes.

AR-15 Lower Parts Kit: includes all parts needed to complete the lower receiver including pistol grip, mil-spec safety selector, and trigger/fire control group.

Lower Assembly: comes with complete buffer tube assembly including buffer, buffer spring, six-position buffer tube, latch plate, castle nut, and butt stock based on original Colt design.

Charging Handle: standard size, made from 6061 aluminum.

Please note: This build kit requires that the builder complete the 80% lower receiver themselves, but that’s the rewarding part of the experience (and 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.