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HK MR556 A1 5.56/.223 Rifle
Heckler & Koch GmbH (HK) is a German defense manufacturing company that manufactures handguns, rifles, submachine guns, and grenade launchers. The company is located in Oberndorf in the state of Baden-Württemberg, and also has subsidiaries in the United Kingdom, France and the United States. The company's motto is "Keine Kompromisse!" meaning "No Compromises!" HK provides firearms for many military, paramilitary units, many other counter-terrorist and hostage rescue teams. Some of their more notable products include the MP5, UMP submachine guns, the G3, HK417 battle rifles, the HK33, G36, HK416 and MR556A1 assault rifles, the MG5, HK21 General-purpose machine guns, the MP7 personal defense weapon, the USP series of handguns, and the high-precision PSG1 sniper rifle. HK has a history of innovation in firearms, like the use of polymers in weapon designs and an integral rail for flashlights on handguns. HK also developed modern polygonal rifling, noted for its high accuracy, increased muzzle velocity and barrel life. HK has used the operating systems for small arms blowback operation, short-recoil, roller-delayed blowback, gas operation via Short-stroke piston, and gas-delayed blowback.
A direct descendent of the HK416, the MR556A1 is a semi-automatic rifle developed by Heckler & Koch as a premium level commercial/civilian firearm with match rifle capability. Like the HK416, the MR556A1 is a major product improvement over conventional AR-type carbines and rifles.
The MR556A1 uses the HK proprietary gas piston operating system, employing a piston and a solid operating “pusher” rod in place of the gas tube normally found in AR15/M16/M4-style firearms.
This method of operation virtually eliminates malfunctions that are common to direct impingement gas systems since hot carbon fouling and waste gases do not enter the receiver area. This is the same key feature critical to the success of the HK416 rifles used by leading military and law enforcement customers.
The MR556A1 is produced in the USA using American and German made components. The MR556A1 uses many of the same assemblies and accessories originally developed for the HK416 including the HK free-floating four-quadrant rail system.
The HK Free Floating Rail System (FFRS) handguard has four MIL-STD-1913 “Picatinny” rails and allows all current accessories, sights, lights, and aimers used on M4/M16-type arms to be fitted to the MR Series. The HK rail system can be installed and removed with simple tools and returns to zero when reinstalled.
The MR556A1 also has a Picantinny rail machined into the top of its upper receiver for mounting optics and mechanical sights. Unlike earlier prototypes, major subassemblies, including the MR556A1 upper receiver/barrel assembly, are fully interchangeable with other high quality AR-style firearms. MR556A1 upper receiver kits can be used to retrofit competing legacy AR systems.
Like the famous HK416, the MR556A1 uses a German-made barrel produced by Heckler & Koch’s famous cold hammer forging process. The highest quality steel is used in this unique manufacturing process producing a barrel that provides superior accuracy and long service life.
But unlike the HK416, the MR556A1 does not use a chrome-lined barrel. Chrome-lining can sometimes mask bore imperfections and negatively affect accuracy. For the new series of Heckler & Koch semi-automatic MR rifles, HK designers and engineers believe best accuracy comes with an unlined bore.
Used with the HK Free Floating Rail System, the barrel does not touch the handguard, ensuring the barrel is truly free-floating for maximum accuracy.
The unchromed barrel has an internal profile of 6 lands and grooves with a 1 in 7 inch (178 mm) twist. It is also moderately “swagged” with a slightly smaller internal diameter at the muzzle end than the chamber end. This feature has a positive effect on bullet accuracy and velocity. The thick, heavy contour 16.5-inch MR556A1 barrel also contributes to its excellent accuracy.
A precise enhanced two-stage trigger adds significantly to the accuracy of the MR556A1 and an extended latch charging handle makes operating the rifle with a telescopic sight easier. The retractable buttstock can be locked into a solid, non-moving position by tightening an Allen screw in the bottom of the stock. Special target rifle takedown pins ensure the upper and lower receivers are firmly mated for accurate performance.
Designed to function with a wide variety of high quality 5.56 x 45 mm ammunition, the MR556A1 uses a C.I.P. dimensioned chamber (a chamber with dimensions specified by the Commission Internationale Permanente).The MR556A1 also functions reliably with most quality Caliber .223 Remington ammunition.
The MR556A1 is being produced with the same commitment to quality as German-made HK firearms. By using joint U.S./German manufacturing, Heckler & Koch leverages the relative strengths of two continents to make the preeminent AR-type firearm, combining the designs innovations of the USA and Germany into one new product.
The MR556A1 rifle includes rifle, HK 30-round steel magazine, set of Troy Industries Micro mechanical sights, HK multi-tool,lock, and case.
Manufacturer Number MR556-A1
Type Long Gun
Barrel Length 16.5"
Overall Length 37.68" w/ Stock extended
Capacity 30 rds
Miscellaneous 6 lands & grooves, right twist, 1 in 7 in
Weight 7.64 lbs
PLEASE NOTE: If you live in a magazine restricted state we remove the hi cap mag and will be glad to substitute with a 10 round mag IF AVAILABLE. If a 10 round mag is not available we will remove the hi cap magazine from the shipment. We cannot ship prohibited magazines to out of state addresses. There will be no substitutions or discounts offered for removal of mags.
It is your responsibility to be familiar with your current local gun laws BEFORE placing your order. Please feel free to email us with questions you may have.
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