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300 Blackout AR 15 Pistol Kit (7.5″ Nitride Barrel & 7″ Quad Rail) w/ 80% Lower

$650.00 $570.00 (You Save $80.00)

Complete Pistol Build Kit - 300 Blackout (7.5" Barrel & 7" Free Floating Quad Rail) AR 15
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SKU: UA300PHB7.517(P)-(7)FFQ_Budget


For the AR builder who wants an accurate, compact, functional, and lightweight AR pistol build kit chambered in .300BLK, look no further. Our 7.5″ pistol upper with free float quad rail features classic picatinny rails that allow for plenty of attachments. With an included bolt carrier group and standard charging handle, all you need to do is complete your 80% lower, assemble your rifle, and you’re ready to fire.  A 1:7 twist rate and pistol gas system offers the perfect balance of stabilizing lighter supersonic 300 blackout loads, without sacrificing the ability to reliably shoot heavier subsonic loads.

Mil-Spec Quality and Accuracy

Our 300 blackout pistol upper features a mil-spec 4150 chrome moly steel barrel with M4 feed ramps for guaranteed feeding and reliability. Because our barrels do not use chrome lining, you’ll enjoy superior accuracy, too. We heat-treat every barrel to a hardness rating of RC 28 to 32, creating stronger rifling that’s more resistant to wear than any other barrel on the market. This negates the need for chrome lining entirely, while still providing superior durability. The upper assembly also features a standard flat Top M4 receiver, housing a quality, mil-spec charging handle and chrome-lined bolt carrier group. Everything is manufactured to ISO 9002 quality control standards, ensuring the highest quality upper possible.

300 Blackout Pistol Barrel Features:

  • .300 AAC blackout chamber
  • 7.5″ with parkerized finish
  • 4150 chrome moly steel
  • Heavy profile
  • 1:7 twist rate
  • 5/8 x 24 thread pitch
  • A2 birdcage flash suppressor

300 Blackout Receiver Features:

  • 7″ free floating quad rail
  • Pistol-length gas system (0.076 Hole)
  • Low profile gas block (0.750)
  • M4 flat top upper
  • M4 feed ramps
  • Pistol gas tube
  • Charging handle
  • Chrome-lined BCG

300 Blackout Build Kit Extras:

  • Shockwave pistol brace and tube
  • Classic lower parts kit
  • 7075 forged lower receiver

Ships Straight to Your House!

There is absolutely no paperwork required! You do not need to deal with any FFL transfers and fees, and there’s no waiting at your local gun store while that PICS check takes forever. The only part of your AR pistol that’s considered a firearm is the stripped lower. This kit is legally not a firearm, so we can ship it directly to your front door.

It is your responsibility to fully understand all applicable laws and regulations regarding purchase and ownership of uppers with a barrel length of less than 16″.

Please note: This AR-15 Build Kit requires that the builder completes the 80% lower receiver themselves, but that’s the fun part (and the only way to build your own AR-15 without the need of an FFL transfer or serialization).

No FFL required Made in the USA Lifetime Warranty

300 Blackout AR 15 Pistol Kit (7.5″ Nitride Barrel & 7″ Quad Rail) w/ 80% Lower

$600.00 $500.00 (You Save $100 )

$600.00 $500.00 (You Save $100 )
Save For Later
Save For Later

Free Shipping on all orders $325+!

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    Isidro R.

    Great Buy

    This was my first build and it turned out amazing. I put a spikes tactical waterboarding instructor lower kn my kit and it looks amazing. 10/10 will and have buy again


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