# HK MR556 A4 5.56x45mm 11in Black

**Brand:** Heckler & Koch
**Category:** AR Style Rifles
**Caliber:** 5.56 NATO

## Specifications

- **Caliber:** 5.56 NATO
- **Barrel Length:** 11"
- **UPC:** 642230269439
- **SKU:** UCBJ1QlAt

## Description

The HK MR556 A4 is an AR-pattern rifle chambered in 5.56x45mm with an 11-inch threaded barrel and M-LOK handguard. It ships with a 30-round magazine and comes in a black finish. The 11-inch barrel places this in a short-barreled rifle configuration; transfer requires additional federal paperwork.

### Key Specifications
- **Brand**: HK
- **Model**: MR556 A4
- **Caliber**: 5.56x45mm
- **Action**: Semi Auto
- **Capacity**: 30 rounds
- **Barrel Length**: 11 inches
- **Color/Finish**: Black

### Detailed Features
- 11-inch threaded barrel
- M-LOK handguard
- 30-round magazine included
- Black finish throughout

## Frequently Asked Questions

**Q: What caliber is the HK MR556 A4?**

A: The MR556 A4 is chambered in 5.56x45mm, also compatible with .223 Remington.

**Q: Who makes the MR556 A4?**

A: The MR556 A4 is made by HK (Heckler & Koch).

**Q: What type of firearm is the HK MR556 A4?**

A: It is a semi-automatic AR-style rifle.

**Q: What is the barrel length of the HK MR556 A4?**

A: The barrel is 11 inches long and is threaded.

**Q: How many rounds does the HK MR556 A4 hold?**

A: It ships with a 30-round magazine.

**Q: Is the HK MR556 A4 barrel threaded?**

A: Yes, the 11-inch barrel is threaded.

**Q: Does the HK MR556 A4 have an M-LOK handguard?**

A: Yes, it comes with an M-LOK handguard.

**Q: Where can I buy the HK MR556 A4?**

A: Compare current vendor offers on this page.

## What Reviewers Say

*Quoted verbatim from YouTube reviews. Each link opens the video at the moment quoted.*

> Inherent feel of this rifle. This rifle feels incredibly solid and high quality.
>
> — [Colion Noir](https://www.youtube.com/watch?v=ZsnApWGaQa4&t=165s)

> This rifle sits. It sits. And you notice something? No gas blowback. No gas blowback. Let me tell you something. Gas blowback sucks.
>
> — [Colion Noir](https://www.youtube.com/watch?v=ZsnApWGaQa4&t=324s)

> Good thing and the bad thing about a gun that is so well built and overengineered like this particular gun is it's heavy.
>
> — [Colion Noir](https://www.youtube.com/watch?v=ZsnApWGaQa4&t=521s)

> Either way you get the point the trigger on this gun is phenomenal phenomenal I have no desire to change.
>
> — [Colion Noir](https://www.youtube.com/watch?v=ZsnApWGaQa4&t=1077s)

## What Customers Say

*AI-generated insights from customer reviews*

Owners of the MR556 A4 in this configuration appreciate the short, maneuverable profile paired with HK's reputation for tight tolerances. The 11-inch barrel and M-LOK handguard draw consistent praise from those who want a compact platform without sacrificing rail space for accessories.

The threaded barrel is a practical plus for suppressor-ready setups, though the added federal paperwork for the short-barreled configuration is a real barrier for some buyers. Those who clear that hurdle tend to be satisfied with the result.

Value relative to the price is the most common debate. The MR556 A4 commands a premium over most domestic AR-pattern options, and opinions split on whether the HK fit-and-finish justifies the cost difference. Trigger feel is functional but not widely praised as a standout.

## Pricing

**8 offers available**

| Vendor | Price |
|--------|-------|
| Impactguns Com | $3534.79 |
| Bereli | $3549.00 |
| Gunbuyer Com | $3749.00 |
| Kygunco Com | $3749.00 |
| Classicfirearms Com | $3749.00 |
| Grabagun Com | $3749.00 |
| Primaryarms Com | $3749.00 |
| Guns Com | $3786.99 |

## Similar Products

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*Data from [GunsNation](https://gunsnation.com)*