HK416 / MR556 Barrels / Gas Blocks

Heckler and Koch Gas Block Pin for HK416 and MR556 This is the retaining pin for an HK416 gas block. A must-have, as HK recommends using new pins once they are removed or damaged.  Size: 5 x 18 mm.

H&K MR556 A4 and HK416 A5 Gas Vent Screws German gas vent screw for MR556 A4 gas block. Specifications: Factory reference: 1.3mm is the common factory vent screw size for MR556 A4 Sizing reminder: Larger mm equals more venting, Smaller mm...

Heckler and Koch Complete Piston Rod Assembly for your HK416, HK MR556, HK417, and HK MR762 A great replacement or spare to keep on hand. Compatible With: HK416, MR556 HK417, MR762 Please Note: Does not fit barrels less than 10 inches.

HK MR556, HK416 & G36, SL8 Gas Piston Ring Replacement Combo Set - 3 Rings This is a high wear common repair & replacement item. The gas rings are prone to periodic breakage & wear, tear and require them to be replaced periodically...

HKP Gas Piston Ring Replacement Combo Set- 3 Rings The gas rings are prone to periodic breakage and wear and tear and require them to be replaced periodically. These are some of the most common breakage parts we see that need to be replaced on these...

HKP (9mm) Thread Protector For Barrels - Threaded 1/2x28 A must-have accessory to safeguard the threads on your threaded barrel, this thread protector is the finest available. It is the standard thread protector included with all HKPARTS threaded pistol...

HK 416, MR556 Barrel Nut Installation & Removal Tool New US manufactured barrel nut removal and installation tool. Each tool has the provision installed to allow the use of an off the shelf 1/2" torque wrench to be used while removing and installing...

H&K Heckler and Koch Complete Vented Upper Gas Block for HK MR556 and HK416 10.4" Barrels New HK German manufacture newest "VENTED" version direct from HK Germany. Great upgrade part for existing 10.4" uppers that have the older style non-vented gas...

Heckler and Koch Barrel nut for MR556A1 rifle All steel barrel nut. This item is 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...

Nefarious Arms - NA5 HK 416 Adjustable Gas Block Nefarious Arm user configurable 2-position adjustable gas block compatible with 11″ – 20″ A1 MR556 and HK416 barrels.  Each gas block ships with 6 vent screws, a screwdriver,...

Heckler and Koch Low Profile Complete Gas Block for HK MR556, HK416, HK German Factory slimline, low-profile gas block for the HK416 and HK MR556. This is the factory-correct gas block found on the MR556. Correct gas block to use with...

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...