Description

The Heckler & Koch MR556 A4 is a premium semi-automatic 5.56×45 mm NATO rifle built on the legendary HK416/MR series design and updated with A4-series features for modern shooters. It uses a short-stroke gas piston system that avoids channeling hot carbon into the action, resulting in cleaner operation and reduced wear compared with direct-impingement ARs. The A4 version adds a two-position adjustable gas block (for suppressed or unsuppressed firing), fully ambidextrous controls, a slim M-LOK free-float handguard, and a six-position adjustable buttstock — blending HK’s battle-proven reliability with commercial versatility for defense, sport, or range use.