HK416 / MR556 Receivers / Uppers

Heckler and Koch's Enhanced HK416 and HK416 Buffer Spring - HK German The HK MR556/416 buffer spring will also work with other AR-15 and M-16 rifles. It is a high-wear item and a must-have replacement part. Compatible With: HK416, MR556 HK416 A5 HK...

HK German Enhanced Ambidextrous HK416 A5 Bolt Release Factory HK ambidextrous magazine paddle catch/release. Compatible With: HK416A5 HK MR556 A4

HK German HK 416, MR556 Ejection Port Cover In FDE HK manufactured newer polymer style cover assembly found on the latest HK 416 & MR556's. This item can also be used on other AR15 style projects to enhance the build with the finest ejection port...

HK 416, MR556 A5 Style Extended Length Castle Nut Unlike the factory German A5 castle, our A5 extended buffer tube castle nut is compatible with both mil-spec & commercial buffer tubes.  Crafted from ordnance grade steel and nitrided for a...

Heckler and Koch HK416, HK MR556, HK MR762 Buffer Retainer Pin Compatible With: HK416, MR556 HK MR762

H&K HK MR556/416 Ejection Port Cover HK manufactured newer polymer style cover assembly found on the latest HK 416 & MR556. This item can also be used on other AR15-style projects to enhance the project with the finest ejection port cover...

Heckler and Koch HK MR556, HK MR762, 416/417 Buffer Retaining Pin New HK German proprietary HK designed buffer pin unique to the HK 416 and MR 556 series.  Compatible With: HK416, MR556 HK MR762 HK M27

H&K HK MR556/MR762/416/417 Takedown Pin Detent Spring New HK German manufacture. Detent spring for the rear takedown pin. Compatible With: HK MR556 HK 416 HK MR762 HK 417

Heckler and Koch HK416 and HK MR556 Ejection Door Lock Bolt or Roll Pin Compatible With: HK416 A1, A3, A5 HK MR556 A1, A4

H&K HK416 A5 Factory German Extended Castle Nut Original HK Factory German steel 416 A5 Extended Castle Nut. Perfect for MR556, HK 416 A5 builds, or upgrades. 

H&K HK MR556/MR762/416/417 Rear Lower Receiver Locking Pin This is the rear 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 lower receivers and improve...

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