HK416 / MR556 Receivers / Uppers

H&K HK MR556/416 E1 Charging Handle - Ambidextrous HK's design boasts a smooth & easy to release latch with an enhanced oversized charging handle.  Compatible With: HK MR556 HK 416 Other AR15, M4 & M16 applications

Ergo AR-15 Castle Nut for Buffer Tubes - US Made Steel Castle-nut for AR buffer tubes fits both mil-spec and commercial buffer tubes alike.  Compatible With: HK416, MR556 AR-15 style platforms

H&K HK MR556 Receiver Take Down Tool This part is the tool used to tighten down the stock movement on the E1/E2 stock. Each tool will be stored in the rear of the E1/E2 stock. Compatible With: HK MR556 Please Note: We get...

HK MR556 & HK416 Buffer Tube Wrench The perfect metric wrench to remove and install the MR556 & HK 416 castle nuts on the buffer tube. A perfect addition to have on hand for OTB or other HK buffer tube upgrades, etc. Made from all steel, heat...

HK 416, MR556 End Plate For Receiver & Buffer Tube New HK German manufacture. Compatible With: HK MR556 & HK 416 upper receiver/buffer tubes

HK Haus Buffer Retainer for HK416, HK417 New HK USA manufacture for the HK416 and HK417 family of firearms. Made from stainless steel.

Heckler and Koch Castle Nut for Buffer Tube for HK416 and HK MR556 New HK German manufacture. This buffer tube castle nut will fit both mil-spec and commercial buffer tubes. All steel manufacture. With HK round tool attachment points as well as...

H&K HK MR556 Front Lower Receiver Locking Pin With Spring Loaded Detent This part is the front (large) takedown pin with ball detent and locking mechanism installed. The idea behind this type of system is to decrease the movement of the upper and...

HK German HK 416, MR556 Ejection Port Cover Door Assembly Complete This is the newer polymer style cover found on the latest HK 416 and MR556's. This is the complete ejection port door assembly needed on all AR15 or MR556/HK416 models. Can also be used...

Heckler and Koch Magazine Catch Spring for HK 416, HK MR556 and HK417, MR762 HK German manufacture. Compatible With: HK416, MR556 M27 HK417, MR762 G28 AR15, M4, M16 firearms

Ejection Port Axle - Steel- HK 416 New HK USA manufacture for the HK 416 family of firearms. This is the axle that holds the ejection port cover in place on the upper receiver. 

HK German Stripped HK MR556 Upper Receiver New factory German incomplete and unmarked MR556 upper receiver. Compatible With: HK MR556 HK MR223 HK 416 Do you need a matching lower for your build?  STS416 A5 LOWER - Specialized Tactical...