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AR 15 Pistol Kit – .300 AAC Blackout (10.5″ Stainless Barrel & 10″ MLOK Handguard) w/ 80% Lower

$777.95 $689.98 (You Save $87.97)

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SKU: UA300PHB10.517(SS)-(10)MLOK-BK


If you’re looking for a pistol-sized AR-15 that shoots the .300 AAC blackout caliber, look no further.  This is a great build kit for just that purpose.  For this particular kit, we decided on a pistol gas system and barrel to make better use of the ballistics associated with supersonic and subsonic .300 BLK rounds. Additionally, if you decide to get a suppressor later (through legal means, of course), the 10.5″ length of this kit’s barrel will allow either type of .300 BLK you feed it to reach optimal velocity and stability.

This kit features a 10.5″ stainless steel barrel as previously mentioned.  You also get a 10″ free float M-Lok handguard for mounting accessories and the Shockwave blade pistol stock kit to wrap this build kit up into a sweet little package.


Gas System: Pistol-length
Barrel Profile: Heavy
Barrel Steel: 416R
Barrel Finish: Stainless steel
Chrome Lining: No
Muzzle Thread: 5/8 x 24
Chamber: .300 BLK
Twist Rate: 1:8
Barrel Extension: .300 AAC Blackout
Gas Block Size: .750″
Gas Block Type: Low-profile
Muzzle Device: A2 Flash hider
Receiver Material: Forged 7075 T6
Receiver Type: A4
Handguard Type: 10″ M-Lok
Bolt Carrier Group Included: Yes
Bolt Steel: 9310 steel, magnetic particle inspected
Bolt Carrier Profile: Full-auto
Charging Handle Included: Yes

Benefits of the 10.5” Pistol-Length SS AR 15 Rifle Kit:

  • 100% legal to own and ship to your front door
  • Not considered a firearm – no FFL paperwork needed!
  • 416R stainless barrel and Freedom 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: 10.5″, pistol-length, 416R stainless steel, chambered in .300 BLK, 1:8 twist rate, .750″ low-profile gas block, 10″ 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, 5.56, and .300 BLK 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 Parts Kit: Includes complete, mil-spec AR-15 parts kit. Features MOE trigger guard and Enhanced Polished Trigger (EPT).

Charging handle: Standard 7075 Forged charging handle.

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).

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″.

AR 15 Pistol Kit – .300 AAC Blackout (10.5″ Stainless Barrel & 10″ MLOK Handguard) w/ 80% Lower

$700.00 $629.99 (You Save $70.01 )

$700.00 $629.99 (You Save $70.01 )
Save For Later
Save For Later

Free Shipping on all orders $325+!


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