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300 Blackout (7.5″ Barrel & 7″ Free Floating Quad Rail) AR 15 Complete Pistol Build Kit #2

$650.00 $550.00 (You Save $100.00)

300 Blackout (7.5" Barrel & 7" Free Floating Quad Rail) AR 15 Complete Pistol Build Kit #2
300 Blackout (7.5" Barrel & 7" Free Floating Quad Rail) AR 15 Complete Pistol Build Kit #2
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Free Shipping on all orders $325+!

SKU: UA300PHB7.517(P)-(7)FFQ_Budget


For the AR builder who wants the most accurate, compact, functional, and lightweight 300 Blackout Pistol Build Kit, look no further. Our 7.5″ Pistol Upper with Free Float Quad Rail features an all-mil-spec construction with classic Picatinny rails that allows for plenty of attachments. With an included bolt carrier group and standard charging handle, this Pistol Upper ships ready to fire, no guesswork and no extra steps needed, just complete your lower receiver and you are ready to go.  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 heavy subsonic loads.

Mil-Spec Quality and Accuracy

Our 300 Blackout Pistol Upper features a mil-spec 4150 Chromoly 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. This Pistol Upper 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.


Gas System: Pistol-length
Barrel Profile: Heavy
Barrel Steel: Chrome moly vanadium
Barrel Finish: Parkerized
Chrome Lining: No
Muzzle Thread: 5/8×24
Chamber: .300BLK
Twist Rate: 1:7
Barrel Extension: .300BLK
Gas Block Size: .750″
Gas Block Type: Low-profile
Muzzle Device: A2 Flash hider
Receiver Material: Forged 7075 T6
Receiver Type: M4
Handguard Type: 10″ lightweight M-Lok free float
Bolt Carrier Group Included: Yes
Bolt Steel: 9310 steel, magnetic particle inspected
Bolt Carrier Profile: Full-auto
Charging Handle Included: Yes

Benefits of the 7.5” Pistol-Length Nitride AR 15 Rifle Kit:

  • 100% legal to own and ship to your front door
  • Not considered a firearm – no FFL paperwork needed!
  • Parkerized steel barrel and parts kit ensure sub-MOA accuracy
  • Prebuilt upper with gas system removes the guesswork of rifle making
  • Includes bolt carrier group, free-floated M-Lok handguard and lower parts kit

AR 15 Rifle Kit Details (Expanded):

Barrel: 7.5″ pistol-length parkerized chrome moly vanadium steel, chambered in .300BLK, 1:7 twist rate, .750″ low-profile gas block, 7″ free-float M-Lok handguard, with an A2 “birdcage” flash hider.

Upper Receiver Assembly: Forged from 7075 T6 aluminum, hard-coat anodized in black for durability, features M4 feed ramps, and are made in the USA.

Bolt Carrier Group: The bolt carrier is made from 9310 steel and has a staked gas key and black nitride finish. The bolt itself comes complete with an extractor spring and O-ring insert.  It accepts .223, 5.56mm, and .300BLK calibers (though you should NEVER attempt to use a caliber for which your rifle is not chambered), and is magnetic particle inspected.

80% Lower Receiver: Choose to receive a forged or billet Fire/Safe 80% lower receiver.  Our lower receivers are anodized to match the upper receiver perfectly. and they come ready for machining of the trigger pocket and drilling of the safety selector and trigger pin holes.

AR-15 Lower Parts Kit: includes all parts needed to complete the lower receiver including pistol grip, mil-spec safety selector, and trigger/fire control group.

Lower Assembly: comes with complete buffer tube assembly including buffer, buffer spring, six-position buffer tube, latch plate, castle nut, and butt stock based on original Colt design.

Charging Handle: standard size, made from 6061 aluminum.

Please note: This build kit requires that the builder complete the 80% lower receiver themselves, but that’s the rewarding part of the experience (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 (7.5″ Barrel & 7″ Free Floating Quad Rail) AR 15 Complete Pistol Build Kit #2

$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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