AR15 Build Kit - .300 AAC Blackout (16" Stainless Barrel, 1:8 Twist & 13.5" M-Lok Handguard)

Finally, there's an easy way for you to get up and running when it comes to the world of the .300 AAC Blackout AR-15.  We put together this build kit just for you, the lucky shooter about to assemble a custom black rifle made for operatin'.

This build kit gets you a 16" stainless (match-grade) barrel with a 1:8 twist rate to accommodate the most popular .300 AAC supersonic and subsonic loads.  You also get our ever-popular 13.5" free floating, lightweight M-Lok handguard.  You supply the mags, lower receiver, and ammo (regular .223 / 5.56mm parts work perfectly with the .300BLK cartridge), and either sights or optics of your choice, and you're good to go.

What’s Included

This kit is not a firearm. It includes an assembled upper receiver, bolt carrier group, lower parts kit, and buffer assembly with buttstock. It does not include the component to make a firearm: A stripped lower receiver. Pair this rifle kit with an AR-15 80% lower receiver and AR-15 jig to fabricate a receiver, sold separately.

New builder? This guide explains 80 percent lowers.

AR-15 Rifle Kit Specs

Barreled uppers are assembled in-house before shipment.

Barrel

• Chamber: .300 AAC Blackout
• Contour: M4/Government
• Length: 16”
• Twist Rate: 1:8
• Gas System: Carbine
• Gas Block Dia: 0.750”
• Muzzle Threads: 5/8x24
• Feed Ramps: M4
• Material: 416R Crucible Stainless
• Finish: Stainless
• Process: Button Rifled
• Lining: Stainless
• Extension: .30-Cal
• Muzzle: A2 “Birdcage” Flash Hider

Handguard

• Attachment System: 13.5" M-Lok
• Finish: Type III Hardcoat Anodized (Mil-Spec)
• Top Rail: M1913 Picatinny
• Material: Billet 6061-T6 Aluminum
• Attachment: Barrel Nut 

Stripped Upper Receiver

• Profile: M4 Flattop
• Material: Forged 7075-T6 Aluminum
• Finish: Type III Hardcoat Anodized (Mil-Spec)

Bolt Carrier Group

• Profile: M16/Full-Auto
• Steel: Carpenter No. 158 (Mil-Spec)
• Exterior: Phosphate Coating
• Interior: Chrome-Lined
• Gas Key: Staked, Chromed
• Charging Handle: Included

Lower Receiver Parts

• Buffer System: Mil-spec, Carbine
• Buttstock: Mil-spec, M4-type
• Parts Kit: Mil-spec, single-stage

Receiver sold separately

No FFL or serialization is required to fabricate a receiver under federal law. However, state laws vary. Some states require serialization or have banned 80% lowers and gun-making kits. We encourage each and every builder to perform their own research about the state and federal laws that apply to them.