Heckler & Koch MR556 A1 Semi-Automatic Rifle 5.56x45mm NATO 16.5" Barrel (1)-30Rd Magazine Synthetic Stock Black Finish
A direct descendant of the HK416, the MR556A1 is a semi-automatic rifle configuration with match rifle capability developed for civilian users. The MR556A1 uses the HK proprietary gas piston operating system, employing a piston and a solid operating "pusher" rod which virtually eliminates malfunctions common to direct impingement gas systems since hot carbon fouling and waste gases do not enter the receiver area. The HK Modular Rail System (MRS) is truly free-floating for maximum accuracy. The MRS handguard has a more ergonomic design, yet retains many features from the previous FFRS. It uses an HK proprietary keyhole design to allow the attachment of Picatinny rail segments to the handguard. The MR556A1 also has a Picatinny rail machined into the top of its upper receiver for mounting optics and mechanical sights. Major subassemblies, including the upper receiver/barrel assembly, are fully interchangeable with other high quality AR-style firearms. The MR566A1 is produced in the USA from both American and German-made components. The German-made, unchromed barrel is produced by HK's famous cold hammer forging process with the highest quality steel for a barrel that provides superior accuracy and long service life.
Brand: HK
Category: Tactical Rifles
Series: A1
Model: MR556
Caliber: 5.56x45mm NATO
Barrel Length Range: 16" to 16.99"
Gun Platform: AR-Style
Operating System: Gas Piston
Stock Finish Group: Black
Capacity: 30+1
Stock Material: Synthetic
Action: Semi-Auto
Oal: 33.90"- 37.68"
Hand: Right Hand
Sights: Optic Ready
Twist: 1:7"
Magazine Type: OEM
Grips: Black Polymer
Handguards: M-LOK
Receiver Material: Aluminum
Stock Description: Adjustable
Barrel Description: Medium Contour
Barrel Length: 16.50"
Max Capacity: 30
Receiver Finish: Black
Weight: 8.60 lbs
Stock Finish: Black
Caliber Dictionary
The Below Information Has Been Provided From Our Gun Caliber Dictionary And Is Meant For Informational Purposes Only. It Is Not Intended to Describe The Unique Specifications For This Ammunition.
The 5.56X45mm NATO cartridge was designed by James Sullivan, a member of Eugene Stoner's engineering team that developed both the M16 rifle and its original cartridge. The 5.56X45mm NATO was adopted by the U.S. military in 1964 and by NATO in 1980. With bullet diameter of .224-inch, the original M193 military cartridge used a 55-grain bullet at 3250 fps; the current M855A1 cartridge, developed by FN, uses a 62.5-grain bullet at 3020 fps, offering greater range and better penetration. The civilian version of the 5.56X45mm is 223 Remington; the cartridges are dimensionally identical but military chamber dimensions and specifications for military brass are different. It is considered safe to use 223 Remington ammo in a 5.56X45MM NATO chamber, but not a good idea to use 5.56X45mm ammo in a rifle specifically chambered for the 223 Remington. Although the stopping power of .22-caliber bullets remains controversial the 5.56X45mm has served well in now multiple generations of M16 rifles. — Craig Boddington
