A direct descendant of the world-famous HK416, the MR556A1 is the commercial carbine from the same DNA. It offers the battlefield-proven reliability, durability and precision you would expect from a rifle that bears the name Heckler & Koch.
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 and more reliably.
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 elite military and law-enforcement customers have absolute trust in their HKs.
The MR556A1’s barrel is cold hammer forged from the highest quality cannon-grade steel. It has a 1 in 7” twist and a taper-bore configuration, with a slightly smaller diameter at the muzzle for improved accuracy and velocity. And 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.”
AVAILABLE CONFIGURATIONS
Part No. 81000579, UPC 642230262553 – MR556, 5.56mm, Optics ready, 16.5″ medium contour barrel, one 30rd magazine – MSRP $3,499
Part No. 81000580, UPC 642230262560 – MR556, 5.56mm, Optics ready, 16.5″ medium contour barrel, one 10rd magazine – MSRP $3,499
CONFIGURATION AVAILABLE
ID Number | UPC Codes | Description | MSRP |
---|---|---|---|
MR556 Rifle, 5.56mm, Optics Ready - supplied with one magazine, rifle length M-LOK handguard, and medium contour barrel | |||
81000579 | 642230262553 | MR556, 5.56mm, Optics ready, 16.5" medium contour barrel, one 30rd magazine | 3,499 |
81000580 | 642230262560 | MR556, 5.56mm, Optics ready, 16.5" medium contour barrel, one 10rd magazine | 3,499 |
MR556 Spare Magazines and Accessories | |||
81000584 | 642230262607 | MR556, Upper Receiver kit - includes bolt, buffer, buffer spring, rifle length M-LOK handguard and 16.5" medium contour barrel assembly | 2,069 |
251770S | 642230248311 | MR556 5.56mm 30rd magazine (steel) | 59 |
233609S | 642230245334 | MR556 5.56mm 20rd magazine (steel) | 69 |
235642S | 642230246492 | MR556 5.56mm 10rd magazine (steel) | 69 |
236204 | 642230247642 | MR556 9" quad rail handguard | 379 |
50233617 | 642230247635 | HK416 11' handguard | 416 |
51000223 | 642230262157 | MR556 9" M-LOK handguard, black | 289 |
51001100 | 642230262683 | MR556 12.5" M-LOK handguard, black | 299 |
TECHNOLOGY

Highest Quality Steel

MEDIA



SPECS
+Dimensions
Caliber | Stock Extended Length | Stock Retracted Length | Width | Height | Barrel Length |
---|---|---|---|---|---|
5.56 x 45 mm | 37.68 in | 33.90 in | 3.07 in | 9.45 in | 16.5 in |
+Weight
Caliber | Rifle (without magazine) | Magazine (empty 10 round magazine) |
---|---|---|
5.56 x 45 mm | 8.60 lb | .31 lb |
+Other Specifications
Caliber | Magazine capacity | Trigger Pull | Barrel Profile | Sight Radius | Sights |
---|---|---|---|---|---|
5.56 x 45 mm | 10/20/30 rounds | 7.64 lb | 6 lands & grooves, right twist, 1 in 7 in | 14.60 in | Optics ready |
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