Nefarious Arms HK416 / MR556 Barrel, 10.4" LIGHT, 5.56x45mm NATO
Nefarious Arms HK416 / MR556 Barrel, 10.4" LIGHT, 5.56x45mm NATO
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The Nefarious Arms HK416 / MR556 Barrel is engineered for shooters who demand uncompromising performance, precision, and durability. Proudly made in the USA, this barrel is crafted from premium 4150 Chrome Moly steel, cold-hammer-forged for strength, and chrome-lined to ensure years of reliable accuracy. Finished in black manganese phosphate, it’s built to handle heavy use while maintaining peak performance. Whether you’re upgrading your HK416 or MR556 this barrel delivers the reliability and consistency you can trust.
Key Features:
- Caliber: 5.56x45mm NATO
- Barrel Length: 10.4"
- Profile: LIGHT
- Twist Rate: 1:7
- Barrel Extension: A1/A3
- Gas Block Seat Diameter: 19mm (h6 Tolerance)
- Muzzle Threads: 1/2"x28
- Material: 4150 Chrome Moly
- Finish: Black Manganese Phosphate
- Cold-Hammer-Forged for Strength and Consistency
- Chrome-Lined for Years of Accurate Shooting
- Weight:
- Made in USA 🇺🇸
Compatible With:
- HK416 A1/A3
- HK MR556
Compatible Gas Blocks:
- HK A1/A3
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Let customers speak for us
from 51 reviewsNothing but the best.
Wow! I'm so glad I was able to grab the last SOCOM profile 14.5 A5 barrel available for now. IMO the fit and the finish is top notch and can't be matched.
I shot nice thight groups out to 100m... so, I can't complain. Looking back, I wish, I could have gotten at least one more barrel for a future A5 project.
Alan Taylor
Dallas, Texas
Very high quality barrel. I would consider this to be as good if not better than the hk made barrels. The chrome lining is excellent and the overall fit and finish is top class. Very smooth shooting would definitely recommend if you are wanting to build a clone or just looking for a high quality cold hammer forged chrome line barrel.
Just got it last Friday so I haven't shot it yet. I purchased the barrel and had Marvin install it on an MR556A4 upper. The work looks really good (no little nicks or anything), the barrel itself is well-made and it's nice seeing a chrome-lined barrel on an HK MR carbine! Would definitely recommend Marvin's work as well as NA for offering us "civvies" a mil-spec barrel. Kudos!
P.S.- Holly answers the phones there and she was very helpful and polite. You all have a solid employee!
Very high quality and definitely adds pressure to the system.
Excellent option for the MR556A4 and 416 clones.
Marvin and his products are top notch. Perfect fitment, excellent quality. These are the best barrels outside fo factory HK that one can buy!
For your barrel nut torquing a must have precision made tool. Excellent machined quality to use on a number of AR , KAC , Centurion Arms or HK variants.
Nicer than other popular and similar tools I have. protect your barrel extension index pin! Get one!