300 Blackout Pistol Kit (10.5” Phosphate Barrel & 12” Slant M-Lok Handguard) w/ 80% Lower (1:8 Twist)



For shooters who want to maximize their range, accuracy, and style points, we’re introducing the 10.5” 300 Blackout AR Pistol Kit. This A2-profile barrel features a pistol-length gas system and is optimized for handling supersonic and subsonic 300 BLK cartridges with ease. We chose a 1:8 twist rate to provide reliable groupings with either loads, while the cold-forged 4150 CMV barrel goes to work guaranteeing MOA accuracy and incredible barrel life.

Out back, you’ll find a quality SBA Pistol Brace with a 5-position buffer tube. A carbine buffer works in tandem with an enhanced, polished trigger kit to ensure reliable cycling with any loads. Simply grab the optional forged or billet 80% lower, and you’ll have all the parts you need to turn a box of bolts and bits into a rugged, reliable AR pistol in a single day.

300 Blackout Pistol Kit Specs:

Barrel Length: 10.5″
Barrel Profile: A2
Gas System: Pistol-length
Barrel Steel: 4150 Chromoly Vanadium
Barrel Finish: Phosphate 
Chrome Lining: No
Muzzle Thread: 5/8-24
Chamber: 300 Blackout
Twist Rate: 1:8
Barrel Extension: M4
Diameter at Gas Block: .750
Gas Block Type: Low-profile
Muzzle Device: PSA Fluted Flash Can
Receiver Material: Forged 7075 T6 Aluminum
Receiver Type: M4
Handguard Type: PSA 12″ Slant End M-Lok Rail
Bolt Carrier Group Included: Yes
Bolt Steel: Carpenter 158
Bolt Carrier Profile: Full-auto
Charging Handle Included: Yes
Overall Length: 21″

300 Blackout Pistol Kit Features:

  • Includes all parts needed to complete build
  • Optional forged or billet 80% lower
  • Upper ships pre-built and test-fired
  • Enhanced, polished trigger for reliability
  • Not considered a firearm, no FFL required
  • Proudly built in the U.S.A.
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.