.300 Blackout AR 15 Pistol Kit – 7.5″ Parkerized Heavy Barrel, 1:8 Twist Rate with 6.5″ MLOK Handguard

Build a suppressor-ready, subsonic-optimized 300 BLK tack driver.
Building an accurate, reliable 300 Blackout-chambered AR-15 can be a challenging: Your setup must be able to reliably cycle supersonic and subsonic loads, suppressed and un-suppressed, to truly perform. We’ve configured this AR pistol build kit to do exactly that. With a 7.5″ heavy barrel, 1:8 twist rate, and dialed in gas system and buffer assembly, this is the kit you need to build a 300 BLK AR ready eat up and spit out suppressed subsonic loads.
What’s Included
This is not a firearm. It includes an assembled upper receiver, bolt carrier group, charging handle, lower parts kit, and buffer system.
300 BLK Pistol Upper Assembly Specs
Barreled uppers are assembled in-house before shipment.
Barrel

Chamber: .300 AAC Blackout
Contour: Heavy
Length: 7.5″
Twist Rate: 1:8
Gas System: Pistol
Gas Block: 0.750″
Muzzle Threads: 5/8×24
Feed Ramps: .30 Cal
Material: 4150 CMV
Finish: Parkerized
Process: Button Rifled
Lining: None
Extension: M4
Muzzle: Fluted Flash Hider

Handguard

Attachment System: 6.5″ M-LOK
Finish: Type III Hardcoat Anodized (Mil-Spec)
Top Rail: M1913 Picatinny
Material: Billet 6061-T6 Aluminum
Attachment: Barrel Nut 

Upper Receiver

Profile: M4 Flattop
Material: Billet 6061-T6 Aluminum
Finish: Type III Hardcoat Anodized (Mil-Spec)

Bolt Carrier Group

Profile: M16/Full-Auto
Steel: AISI E9310
Exterior: Black Nitride
Interior: Black Nitride
Gas Key: Staked
Charging Handle: Included, Right Side Charging

Lower Receiver Parts

Buffer System: AR-15
Pistol Brace: SBA3 5-Position
Parts Kit: Mil-Spec LPK

Lower receiver assembly sold separately. 

WARNING: Handling firearms parts and accessories can expose you to lead and other petroleum products known to the State of California to cause cancer and reproductive harm. For more information go to: www.P65Warnings.ca.gov

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.

GunBuilders.com only ships within the United States. Federal legislation dictates we cannot ship our products internationally.