Rifle Build Kit (Complete) - 300 Blackout (16" Barrel & 12" Lightweight Keymod Handguard) AR 15



This complete build kit chambered in .300BLK features a 16" barrel and comes with a standard A2 birdcage flash hider and a 12" handguard.  The handguard features a picatinny top rail and keymod attachment system, which gives it a couple different ways to mount attachments such as foregrips or tac lights.

Mil-Spec Quality and Accuracy

The .300 AAC blackout upper assembly features a barrel manufactured from mil-spec 4150 chrome moly steel, which provides superior barrel life and accuracy.  Each barrel is built with the intent of providing 1 MOA accuracy at 100 yards (if you can manage, of course). It also features a carbine gas system to reliably cycle any .300BLK load, light or heavy. Hand-built in the USA, the upper assembly features a standard flat top M4 upper receiver with Type III Hard Coat Anodized finish (mil-spec), and M4 feed ramps.

300 Blackout Barrel Features:

  • .300 AAC blackout chamber
  • 16" with parkerized finish
  • 4150 chrome moly steel
  • Heavy profile
  • 1:8 twist rate
  • 5/8 x 24 thread pitch
  • A2 birdcage flash suppressor

300 Blackout Upper Receiver Features:

  • 12" lightweight keymod handguard
  • Carbine-length gas system (0.125 Hole)
  • Low profile gas block (0.750)
  • M4 flat top upper
  • M4 feed ramps
  • Carbine gas tube
  • Charging handle
  • Chrome-lined BCG

300 Blackout Build Kit Extras:

  • Buffer tube and spring
  • Enhanced stock
  • Lower parts kit
  • 7075 80% forged lower receiver

No FFL Required

This complete .300 blackout build kit is the most effective way to finish your first 300 blackout AR-15 without any guesswork. The entire barrel and gas system are head-spaced and pre-installed, and everything ships to your door with no FFL required and no paperwork needed!

No FFL required  Made in the USA  Lifetime Warranty

Shipping Restrictions

AR-15Lowerreceivers.com only ships within the United States. Federal legislation dictates we cannot ship our products internationally. 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 (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. We try our best to keep our shipping page current, but laws change daily.

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.