5.56mm NATO AR 15 Rifle Kit (16" Nitride Barrel & Classic A2 Handguard) w/ 80% Lower (1:7 Twist) - Blem



Want the most affordable, quality mil-spec AR kit? Love the classic look of a service-issued M4 Carbine? Go for full authenticity and save a ton of cash with this cosmetically “blemished” A2-style build kit. Your black rifle will get dents and dings at the first range day, anyway.

Even with a minor scratch on the receiver or a tiny nick in the handguard, nothing prevents this reliable shooter from performing with any 5.56 or .223 loads you slam through the barrel. Everything about this kit screams “mil-specs”, except for the barrel treatment: We ditched chrome lining in favor of a full nitride / QPQ treatment to provide even more accuracy and better protection against the elements.

Barrel Features & Specs:

  • Barrel Length: 16”
  • Gas System: Carbine
  • Barrel Profile: Government
  • Steel: 4150 CMV
  • Barrel Finish: Nitride / QPQ
  • Chrome Lining: None
  • Muzzle Thread: ½-28
  • Chamber: 5.56 NATO
  • Twist Rate: 1:7
  • Barrel Extension: M4 Feed Ramps
  • Diameter at Gas Block: .750
  • Gas Block Type: F-Marked FSB
  • Muzzle Device: A2 Flash Hider

Upper Receiver Features & Specs:

  • Receiver Material: Forged 7075-T6
  • Receiver Type: Flattop M4
  • Handguard Type: A2/Heat Dissipator
  • Bolt Carrier Group Included: Yes
  • Bolt Steel: 9130
  • Bolt Carrier Profile: Full-Auto (M16)
  • Charging Handle Included: Yes

Build Kit Benefits

  • 100% legal to own and ship to your front door
  • Not considered a firearm – no FFL paperwork needed!
  • 4150 CMV barrel and Classic LPK provides MOA accuracy
  • Prebuilt upper ships ready to fire (test-fired for reliability)
  • Includes optional forged or billet 80% lower receiver

AR 15 Rifle Kit Details (Expanded):

Barrel: 16″ mid-length, 4150 CMV steel with nitride / QPQ treatment, chambered in 5.56 NATO, 1:7 twist rate, classic A2 front sight post/gas block, carbine A2 handguard, A2 “birdcage” flash hider.

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

Bolt Carrier Group: The BCG is made from 9310 steel and has a staked gas key and black nitride finish. Chrome-lined, includes extractor spring and O-ring insert. 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, mil-spec, made from 6061 T6 aluminum.


Please note: This build kit requires that the builder complete the optional 80% lower receiver, 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.