AR-15 Pistol Kit - .300 Blackout (8.5" Barrel & 9" M-Lok Handguard) w/ 80% Lower



.300 AAC Blackout is somewhat a picky caliber, but one thing is for certain, it loves shorter barrels.  Also, they work well with suppressors.  Not to mention they're just a hell of a lot of fun to shoot.  That's why we're bringing you this AR pistol build kit chambered in .300BLK.

So what's in this kit?  Well for starters, you get a prebuilt upper assembly made with an 8.5-inch barrel and a 9-inch lightweight MLOK handguard.  You also get a lower parts kit that comes with a polished trigger for a little smoother performance, a Magpul MOE grip and trigger guard, and SB Tactical's SBA3 adjustable pistol brace.  Finally, and the centerpiece of the kit, you get your choice of forged lower made of 7075 T6 aluminum, billet lower made of 6061 T6 aluminum, or no lower if you've already got this part worked out for yourself.

AR-15 Pistol Build Kit Specs:

Barrel Length: 8.5″

Barrel Steel: Chrome Moly Vanadium

Barrel Finish: Phosphate

Muzzle Thread: 5/8 x 24

Chamber: .300 AAC Blackout

Twist Rate: 1:8

Muzzle Device: Fluted Flash Can

Receiver Material: 7075 T6 Forged Aluminum

Receiver Type: M4

Handguard Type: 9” Lightweight M-Lok

Bolt Carrier Group Included: Yes

Bolt Steel: Carpenter 158

Charging Handle Included: Yes

AR-15 Pistol Build Kit Features:

  • Complete build kit w/ optional lower
  • Includes pre-built .300BLK AR upper
  • High-quality CMV barrel for accuracy
  • Features enhanced, polished trigger
  • Not considered a firearm, no FFL required
  • Proudly built in the U.S.A.
  • Backed by Lifetime Warranty

Barrel: Phosphate-coated, 8.5”, chambered in .300BLK. Made of 4150 CMV steel. Heat-treated. Features 1:8 twist rate. Includes 9” M-Lok handguard, and fluted flash can.

Upper: Made of 7075 T6 forged aluminum. Hard-coat anodized (Type III).

Bolt: Heat-treated. Nitride finish. Carpenter 158 steel.  Full auto profile.

80% Lower: Complete with optional AR-15 80% lower. Mil-spec fittings. Type III Hardcoat anodized finish.

Lower Parts Kit: Mil-spec AR-15 lower parts kit. Enhanced, polished trigger (EPT). Six-position buffer tube. SB Tactical Pistol Brace. Magpul MOE grip. Carbine buffer spring and pistol buffer.

Charging Handle: Standard AR-15 charging handle.

Please note: If completing your AR-15 build using the optional 80% lower, please select an AR-15-compatible 80% jig from the available options on our website.

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 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, Pennsylvania, 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.