MR556A1

 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.” 

CONFIGURATION AVAILABLE

ID NumberUPC CodesDescriptionMSRP
MR556 Rifle, 5.56mm, Optics Ready - supplied with one magazine, rifle length M-LOK handguard, and medium contour barrel
81000579642230262553MR556, 5.56mm, Optics ready, 16.5" medium contour barrel, one 30rd magazine 3,499
81000580642230262560MR556, 5.56mm, Optics ready, 16.5" medium contour barrel, one 10rd magazine 3,499
MR556 Spare Magazines and Accessories
81000584642230262607MR556, Upper Receiver kit - includes bolt, buffer, buffer spring, rifle length M-LOK handguard and 16.5" medium contour barrel assembly2,069
251770S642230248311MR556 5.56mm 30rd magazine (steel)59
233609S642230245334MR556 5.56mm 20rd magazine (steel)69
235642S642230246492MR556 5.56mm 10rd magazine (steel)69
236204642230247642MR556 9" quad rail handguard379
50233617642230247635HK416 11' handguard416
51000223642230262157MR556 9" M-LOK handguard, black289
51001100642230262683MR556 12.5" M-LOK handguard, black299

TECHNOLOGY

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Highest Quality Steel

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We use the same grade steel used in making cannon barrels — for its rifle barrels. Using the famous HK cold hammer forging process, this advanced technology manufacturing produces a barrel that provides superior accuracy and long service life. It is also moderately “swagged” with a slightly smaller internal diameter at the muzzle end than the chamber end. This has a positive effect on bullet accuracy and velocity and the thick, heavy contour MR series barrels also contributes to its precision.

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SPECS

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Dimensions

CaliberStock Extended LengthStock Retracted LengthWidthHeightBarrel Length
5.56 x 45 mm37.68 in33.90 in3.07 in9.45 in16.5 in

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Weight

CaliberRifle (without magazine)Magazine (empty 10 round magazine)
5.56 x 45 mm8.60 lb.31 lb

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Other Specifications

CaliberMagazine capacityTrigger PullBarrel ProfileSight RadiusSights
5.56 x 45 mm10/20/30 rounds7.64 lb6 lands & grooves, right twist, 1 in 7 in14.60 inOptics ready

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