HK416 / MR556 Receivers / Uppers

Enhanced HK German MR556 & 416 Buffer Spring 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: HK MR556 HK416 HK416 A5 HK M27 AR15, M4 & M16

HK German Enhanced ambi 416 Bolt Release - HK 416 A5 The real deal HK German HK416A5 bolt release. Made from hardened steel.

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...

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...

H&K HK MR556/MR762/416 Buffer Retainer Pin Compatible With: HK MR556 HK 416

H&K HK MR556/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: HK MR556 HK 416 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

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...

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: HK MR556 & 416 AR-15 style platforms

HK MR556 & HK416 Ejection Door Lock Bolt/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.