The MR556A1 Upper Receiver Kit includes a complete upper receiver/barrel assembly, bolt carrier assembly, buffer, and buffer spring allowing most high-quality 5.56 mm AR-style rifles to be retrofitted to HK’s pusher rod system.
Complete MR556 Upper Receiver/Barrel Assembly— HK 16.5 inch cold-hammer forged barrel, upper receiver with forward assist, extended convertible charging handle.
HK Free Floating Rail System handguard
Complete MR556 Bolt Group Assembly
Tungsten Filled HK Proprietary Buffer
HK Proprietary Buffer (Action) Spring
HK MR556 Upper kit includes:
- Complete MR556 Upper Receiver/Barrel Assembly— HK 16.5 inch cold-hammer forged barrel, upper receiver with forward assist, extended convertible charging handle, MLOK handguard
- Complete MR556 Bolt Group Assembly
- Buffer and buffer spring included , No front or rear sights !!!
- The MR556A1 Upper Receiver Kit is produced in the USA using American and German made components. The Upper Receiver Kit uses a German-made barrel produced by Heckler & Koch’s famous cold hammer forging technology. The highest quality steel is used in this unique manufacturing process producing a barrel that provides superior accuracy and long service life.
Determined at checkout.
