This latest update to the MR556A1 includes an updated grip and forearm as well as a lighter barrel profile that removes nearly a pound of front-end weight from the rifle.
The MR556A1 is assembled in the USA using US- and German-made components and uses many of the same parts and assemblies developed for the HK416.
Like the HK416, the MR556A1 uses a proprietary HK short- stroke gas piston in place of the direct-gas-impingement system found on lesser AR15-style rifles that propels exhaust gas into the upper receiver to operate the action. In the “closed” HK piston system, exhaust gasses never enter the receiver, which means the HK runs cooler, cleaner. That is where that legendary HK reliability comes from.
When adverse conditions, like dust, sand and mud are introduced, the advantage of the HK system becomes even more drastic. That is why so many of the world’s military and law-enforcement elite customers trust HK.
The MR556A1’s barrel is cold hammer forged from the highest quality cannon-grade steel, with a slightly smaller diameter at the muzzle for improved accuracy and velocity. While the material and cold hammer forging process themselves greatly enhance durability, HK’s processes include many additional steps not taken by other manufacturers to produce superior accuracy and service life, ensuring performance well beyond “mil-spec.”
- Brand : HK
- Category : Tactical Rifles
- Caliber : 5.56x45mm NATO
- Model : MR556
- Series : A1
- Stock Finish : Black
- Action : Semi-Auto
- Barrel Length Range : 16″ to 16.99″
- Sights : None, Optic Ready
- Capacity : 30+1
- Magazine Type : OEM
- Grips : Black Polymer
- Hand : Right
- Handguards : M-LOK
- OAL : 33.90″-37.68″
- Receiver Finish : Black
- Receiver Material : Aluminum
- Stock Description : Adjustable
- Stock Finish Group : Black
- Stock Material : Synthetic
- Weight : 8.60 lbs
- Barrel Description : Medium Contour
Frequently Asked Questions – HK MR556 A1 5.56/.223, 16.5" Medium Contour Barrel, M-LOK, Black, 30rd HK- Heckler and Koch
- How fast does this ship?
- Ships in 1‑3 business days to your licensed D.C. FFL dealer after purchase and registration.
- Do I need registration?
- Yes. DC requires firearm registration, including a mandatory 10‑day waiting period after purchase approval from MPD before pickup. Handguns require registration, magazines <=10 rounds.
- Is this legal in D.C.?
- Yes, provided it complies with D.C. law (registered, no assault features, magazine ≤10 rounds).
- Is the HK MR556 A1 5.56/.223, 16.5" Medium Contour Barrel, M-LOK, Black, 30rd HK- Heckler and Koch suitable for me?
- This HK MR556 A1 5.56/.223, 16.5" Medium Contour Barrel, M-LOK, Black, 30rd HK- Heckler and Koch is popular for uses like guns.
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