Nefarious Arms HK416 / MR556 Barrel, 14.5" SOCOM, 5.56x45mm NATO

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, MR556, or MR223*, this barrel delivers the reliability and consistency you can trust.

Key Features:

• Caliber: 5.56x45mm NATO
• Barrel Length: 14.5"
• Profile: SOCOM
• Twist Rate: 1:7
• Barrel Extension: A1/A3 or A5
• 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: 31.2 oz.
• Made in USA 🇺🇸

Compatible With:

• HK416 A1/A3
  
• HK MR556
• HK416 A5 / MR223*

*Requires A5 Barrel Extension Option

Compatible Gas Blocks:

• Nefarious Arms NA5 Adj. Gas Block
• HK A1/A3

Note:

A5 Barrel Extensions are marked "HAUS" due to an error by the barrel extension supplier. The marking is not visible once installed.