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Heckler & Koch Complete MR556 Upper Receiver Kit 81000584

Heckler & Koch Complete MR556 Upper Reciever and Barrel Assembly, 16.5 in Barrel, 81000584
Heckler & Koch Complete MR556 Upper Reciever and Barrel Assembly, 16.5 in Barrel, 81000584
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Heckler & Koch Complete MR556 Upper Reciever and Barrel Assembly, 16.5 in Barrel, 81000584

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Questions & Answers
Would this H&K model upper be piston; if so is there adjustable gas settings? Expert Answer

The Heckler & Koch Complete MR556 Upper Receiver Kit uses a gas piston setup, however, it is not adjustable.

by Ethan, Gear Expert, September 21, 2022
This upper require special trigger groups? Can you answer this question?
View All Q&A You Have a Question? Ask!
Customer Reviews
Helpful Positive Review
Fantastic Purchase by Zack B, February 29, 2024
Upper kit included very nice HK soft case which I feel deserves to be mentioned in item description. Shipped quickly, in good condition and dropped right onto a milspec lower. Only gripe is that HK stopped shipping these with any irons.
5/5 found this helpful
Read 1 Review

Product Discontinued by Manufacturer

Heckler & Koch Complete MR556 Upper Receiver Kit has been discontinued by Heckler & Koch and is no longer available. Our product experts have helped us select these available replacements below.You can also explore other items in the Gun Parts, AR 15 Parts, Rifle Parts, AR15 Upper Receivers yourself to try and find the perfect replacement for you!

Product Info for Heckler & Koch Complete MR556 Upper Receiver Kit

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 HKs pusher rod system.image

Features of Heckler & Koch Complete MR556 Upper Reciever

  • 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
  • NOTE: The MR556A1 Upper Receiver Kit is not classified as a firearm and can be purchased without a Federal Firearms License ( FFL).

Package Contents:

  • Heckler & Koch Complete MR556 Upper Reciever
  • Bolt
  • Buffer
  • Buffer spring
  • Rifle length M-LOK handguard
  • 16.5" medium contour barrel assembly

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Heckler & Koch Complete MR556 Upper Receiver Kit Accessories

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Heckler & Koch Complete MR556 Upper Receiver Kit Unavailable & Discontinued Models

List of Unorderable Models

  • Heckler & Koch Complete MR556 Upper Reciever Kit, 16.5 in Barrel, 81000584 , MPN: 81000584 , UPC: 642230262607 , Code: 13-URC-MR56UR-81000584
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