Our .300 blackout rifle build kit is hands-down perhaps the most affordable .300 AAC blackout build kit on the market, featuring outstanding quality and accuracy, and a minimalist design. The complete upper assembly chambered in .300BLK comes with a classic A2 handguard, and everything is kept simple and lightweight. This rifle’s upper assembly is reminiscent of the old school rifles from our nation’s previous era and has been put through some of the most rigorous quality controls, and everything’s built in the USA.
Mil-Spec Construction and Quality
For its classic look, our .300 blackout rifle upper is still built to military specifications. Inside the standard flat top M4 upper and 4150 chrome moly steel barrel, you’ll find M4 feed ramps, a chrome-lined bolt carrier group, and standard charging handle. This barrel’s heavy profile guarantees accuracy up to 1 MOA if you’re good enough. The mil-spec carbine gas system and removable A2 birdcage flash hider make switching from supersonic to subsonic loads and going suppressed a breeze.
AR 15 RIFLE KIT SPECS:
Gas System: Carbine-length
Barrel Profile: M4
Barrel Steel: Chrome moly vanadium
Barrel Finish: Black nitride
Chrome Lining: No
Muzzle Thread: 5/8×24
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
Handguard Type: CAR-style/M4-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″
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, 1:8 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).
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.