HK416 / MR556 Barrels / Gas Blocks

Nefarious Arms - Reaction Rod - HK416  The Nefarious Arms HK416 Reaction Rod is used to securely hold the upper receiver in a bench vise so that work may be performed on the muzzle device. It is inserted through the rear of the upper receiver to...

New HK German .223/5.56 Chamber Flute Cleaning Brush This item is ideal to have on hand for cleaning the flutes of the barrel. The flutes have to remain clean for the rounds to be extracted properly. 

Nefarious Arms HK G36/SL8/HK 416/MR556 Gas Piston A great spare, upgrade, or replacement part for your HK. Includes 3 piston rings for a complete drop in replacement part. TiN coated for corrosion resistance.  Compatible with: HK G36 HK416 HK...

HK MR556, HK 416 Barrel Nut Or Socket For Barrel - Aluminum A must have repair and replacement part for removal or when you have any work done to your barrel as the barrel nut may become damaged in the removal and installation processes. Made in the USA...

HK G36, HK SL8, HK 416, & HK MR556 Gas Piston Complete assembly with 3X rings installed and nitrided black. Counts as one US-made compliant part for your SL8-G36 style conversion. This is one of the best parts to use on the conversion as it is one of...

Nefarious Arms HK 416/MR556 10.4" A3 Barrel ***THE BARREL EXTENSION RIM IS MARKED "HAUS" DUE TO AN ERROR BY THE BARREL EXTENSION SUPPLIER.  THE MARKING IS NOT VISIBLE ONCE INSTALLED.  THESE BARRELS ARE GENUINE NEFARIOUS BARRELS AS NEFARIOUS...

Nefarious Arms HK 416 Gas Block Assembly Tool A Nefarious Arms creation for those that like to service or replace their 416 gas block. This assembly tool will effortlessly help you assemble or disassemble your 416 gas block by simply aligning the two...

HKP 416 10.4" 5.56 Complete Upper Kit Complete Each kit includes the complete upper assembly, bolt group, tungsten buffer, & high-reliability SS recoil spring. This upper kit is a complete gas piston HK 416 style upper assembly that will drop on your...

Nefarious Arms HK 416 Barrel Installation and Multi Tool HK416 multitool patterned off a genuine HK 416 wrench with added features.  Use with a traditional 1/2″ torque wrench or the plug-and-socket style torque wrench that utilizes the ball...

Heckler and Koch HK German 10.4" Barrel Non-Vented Gas Block Complete Factory HK NON-VENTED 10.4" gas block. Compatible With: HK416 10.4" uppers HK MR556 to 10.4" conversions

Titanium HK MR556, HK 416 Barrel Nut Or Socket For Barrel A must have repair and replacement part for removal or when you have any work done to your barrel as the barrel nut may become damaged in the removal and installation processes. Made in the USA...

Bore Cleaning Brush For .223/556 Calibers