The HK MR556 delivers military-grade reliability in a civilian-legal platform, engineered with the same piston-driven operating system trusted by special forces worldwide. This 5.56x45mm NATO rifle combines Heckler & Koch's legendary build quality with practical features for serious shooters.
What Makes This Different
Unlike direct impingement systems, the MR556 uses HK's proprietary short-stroke gas piston system that runs cooler and cleaner. The chrome-lined cold hammer forged barrel maintains sub-MOA accuracy through thousands of rounds while the monolithic upper receiver provides a rigid platform for optics. Free-floating handguards and ambidextrous controls set this apart from standard AR-15 configurations.Key Features
- Short-stroke gas piston operating system eliminates gas blowback
- 16.5-inch cold hammer forged barrel with 1:7 twist rate
- Monolithic upper receiver with integrated Picatinny rail
- Ambidextrous safety selector and magazine release
- Free-floating quad rail handguard system
- Adjustable buttstock with multiple positions
- 30-round detachable magazine included
Technical Specs
- Caliber: 5.56x45mm NATO/.223 Remington
- Barrel Length: 16.5 inches
- Overall Length: 33-36.5 inches (stock dependent)
- Weight: 8.9 pounds (unloaded)
- Magazine Capacity: 30 rounds
- Twist Rate: 1:7 inches
- Finish: Black anodized aluminum/phosphate steel
- Country of Origin: Germany

