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Rainier Arms, LLC

Rainier Arms Select 300AAC Blackout Barrel - 16

Rainier Arms Select 300AAC Blackout Barrel - 16
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Availability: Out of stock




There are a number of advantages to polygonal rifled barrels; such as less bullet deformation, resulting in reduced drag as well as prolonged barrel life, not to mention ease of cleaning. These barrels were made to our exact specifications & drawings and made of 416R Stainless steel. We control the manufacturing process to provide the most accurate barrel in its price range. We are so confident in our Select grade barrels that we will offer a 100% money back guarantee within 90 days of purchase, no questions asked. If you aren't completely satisfied with the barrel for any reason, return it for a full refund. Guaranteed to shoot sub-MOA at 100 yards with match ammo. You deserve this confidence inspiring barrel for your next custom build.


    • 416 R ordnance grade stainless steel produced in Germany by the same mill as H&K
    • F bar rated = meaning it is acceptable for use by all Nato country’s
    • Extensions made from 4140 AE = meaning aircraft grade steel
    • Manufacturing proprietary processes creates a stress free product that has a hardened surface on the bore. To improve the wear and longevity
    • M4 feed ramps on extensions to current production standards to ensure conformance between manufactures


      • Barrel Length: 16"
      • Gas Block Seat: .750
      • Rifling: Polygonal 5R
      • Weight: 31 oz
      • Stainless Steel: 416R
      • Feed Ramps: M4
      • Gas System: Carbine
      • Chamber: 300 AAC Blackout
      • Finish: Matte Stainless / Black Nitride
      • Twist: 1X8.5
      • Testing: MPI tested
      • Made in the USA!

Additional Info

Additional Info

SKU RA:553:
Manufacturer Rainier Arms, LLC
Finish No
Barrel Length 16"
Caliber 300AAC
Configuration No
Option No
Gas Length Carbine
Height No
Rail Length No
Mount No
Profile No
Reticle No
Co Witness No
Size No


Customer Reviews (1)

Great to shoot the gonads off gnats...Review by Courageous Lion
I bought one, was very pleased with the accuracy. So I bought two more and now I am triple pleased with the accuracy. I was shooting gnat gonads off at 100 yards with ease. II hand load and found out that the poly barrel builds up pressure a lot quicker so watch your loads. The book starting load with a 147 grain FMC with Lil Gun was enough to blow the primers out. After backing off the starting load two grains I found that load worked well and the velocity was almost the same as the maximum load that was listed in the book. So WATCH your loads with these barrels. This type of rifling has way less blow by then standard rifling. Now, that I've written a great review...WHERE IS MY COUPON? Just kidding guys. Their barrels are great. I have a number of Ultra Match 5.56 and most likely would have bought one of those if they made them in this caliber at the time I bought these. I see that they now have an Ultra Match available in this caliber but it is missing one thing....BLACK. I hate stainless steel silver barrels. I guess I might try one and put some Cerakote on it...yea. that would make sense! Melonite is BETTER because it treats the inside of the barrel as well as the outside...HINT, HINT, HINT Rainier arms...ULTRA MATCH barrels with Melonite QPQ PLEASE!!! (Posted on 8/10/2016)

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