HK MR556 A4 Features
The legendary HK gas piston system reduces fouling and heat transfer into the receiver, making the MR556 ideal for demanding shooting environments. A cold hammer-forged, 6-groove barrel with a 1:7” twist enhances accuracy and barrel longevity, while the M-LOK handguard provides lightweight modularity for accessories. The ambidextrous controls—including the safety selector and charging handle—make this a versatile option for both right- and left-handed shooters.
The 6-position adjustable synthetic stock allows for a customized fit and stable shooting stance, even in dynamic situations. A full-length Picatinny rail on the receiver offers optimal space for optics, irons, or laser modules, and the lack of factory sights gives you freedom to configure as needed. With its smooth 4.5–5.6 lb trigger pull and sleek design, the MR556 A4 offers exceptional control, durability, and battlefield-proven engineering.
HK MR556 A4 Specifications
- Brand: HK (Heckler & Koch)
- Model: MR556 A4
- Caliber: 5.56x45mm NATO
- Action: Semi-Auto
- Operating System: Gas Piston
- Capacity: 30 + 1
- Barrel Length: 11″
- Barrel Description: Threaded
- Thread Pattern: 5/8″x24
- Barrel Material: Steel
- Barrel Finish: Black
- Twist Rate: 1:7″
- Receiver Description: Picatinny Rail
- Receiver Finish: Patriot Brown
- Stock Type: 6-Position Adjustable
- Stock Material: Synthetic
- Grip: Black Polymer
- Handguard: M-LOK
- Trigger Pull Weight: 4.50 – 5.60 lbs
- Safety: Ambidextrous Safety Lever
- Sights: None (Optics Ready)
- Overall Length: 26.50″
- Height: 7.50″
- Width: 3.07″
- Weight: 6.61 lbs
| Barrel Length | 11 |
|---|---|
| Caliber | 5.56 |
| Capacity | 30 |
| Condition | New in Box |
| Finish Per Color | Patriot Brown |
| Manufacturer | Heckler and Koch |
| Manufacturer Part Number | 81001201 |
| Model | MR556 A4 |
| Type | Semi Auto Handguns – Tactical |
| UPC | 642230271050 |
