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300 Blackout Build Kit

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300 Blackout Build Kit

We put together a selection of affordable, easy-to-complete 300 Blackout Build Kits so you can avoid those high prices at the local gun store. These AR-15 pistol and rifle kits include a top-of-the-line 416R stainless or mil-spec 4150 steel barrel for MOA accuracy. Each kit features an optional billet or forged 80% lower. 

300 Blackout is an incredibly versatile round, offering medium-range accuracy with supersonic loads, and whisper-quiet shot placement with subsonic loads. Enjoying all that performance means investing in a quality build kit, which you can find right here.

What’s Included

To ensure reliable performance, every 300 Blackout upper in each kit is pre-built and ships ready to fire out of the box. Each Build Kit includes every part you need to complete your rifle or pistol:

  • Complete upper receiver assembly
  • Carbine or pistol gas system
  • AR-15 lower parts kit
  • Complete buffer assembly
  • Butt stock (rifle) or pistol brace
  • M16 full-auto bolt carrier group

Finish Your Build with an 80% Lower

Select an optional billet or forged 80% lower when you pick your build kit, and you’ll have every part you need to finish your rifle or pistol. Just pick an AR-15 80% jig from our available options, and you can complete your build in a single day.

Benefits of Our 300 Blackout Build Kits:

  • Complete AR-in-a-box (w/ 80% lower)
  • Not considered a firearm, no FFL required
  • Pair with optional billet or forged 80% lower
  • Kits are compatible with any AR-15 80% jig
  • Ships straight to your front door
  • Backed by Lifetime Warranty
  • Proudly built in the U.S.A.


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