HK MR556 A4 For Sale 16.5″ – Precision-Driven. Battle-Tested. Commercial-Ready.

The MR556 A4 is the latest evolution of HK-USA’s civilian adaptation of the legendary HK416—a rifle known worldwide for its uncompromising performance in the hands of elite military units. Built for shooters who demand unmatched reliability, durability, and control, the MR556 A4 delivers top-tier capability in a commercial-ready package.

Chambered in 5.56x45mm NATO, the MR556 A4 features HK’s proven short-stroke gas piston system—a design that keeps carbon and heat out of the receiver, minimizing fouling and wear on internal components. The result? Longer run times, reduced maintenance, and superior performance over traditional direct-impingement AR platforms.

Key Performance Features:

• Adjustable gas regulator for seamless transition between suppressed and unsuppressed shooting

• Fully ambidextrous controls for intuitive operation by right- or left-handed users

• Slim, lightweight profile enhances balance, mobility, and weapon handling under any conditions

Whether for duty use, competition, or serious recreational shooting, the MR556 A4 is a refined, precision-built rifle that doesn’t compromise—because your rifle shouldn’t either.

HK MR556 A4 For Sale Specifications