Heckler & Koch MR556: High-Capacity AR15/M4 Steel Magazine

When you’re running a rifle for duty, competition, or personal protection, the details matter. A reliable magazine is as important as the rifle itself — it has to feed cleanly, hold the rounds you need, and survive rough handling. We evaluate gear the way a professional would: by how it performs under stress and how easily it integrates with the rest of your setup.

H&K MR556

When you want to move on a target and not worry about feeding issues, a steel magazine designed specifically for your platform reduces variables. The H&K MR556 steel magazine is built to fit HK’s MR556 rifle and is also compatible with AR15, M4, and M16 style rifles. It holds up to 20 rounds and is a straightforward replacement or spare for shooters who run HK-pattern rifles or standard AR platforms.

Why the H&K MR556 matters for shooters

There are plenty of aftermarket magazines, but the H&K MR556 stands out for fitment and simplicity. Because it’s designed to fit HK’s MR556, you get confident lockup and feed geometry engineered around that rifle’s magwell and feed ramp angles. At 20 rounds capacity, this magazine is useful in jurisdictions where higher-capacity magazines are restricted, or for users who prefer a lower-profile carry and balance point on the rifle.

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Fit and compatibility

Designed for HK’s MR556 platform, the H&K MR556 magazine also fits AR15, M4, and M16-style rifles. If you run multiple rifles with standard AR-style magwells, this magazine simplifies logistics: one magazine type that works across several platforms. For users who own an MR556, buying a magazine engineered for that rifle removes the common worry of imperfect fitment that can plague generic options.

Platform considerations

Because the magazine is steel and follows HK’s design parameters, expect a firm seating feel and consistent engagement with the mag release. If you swap between polymer and steel magazines, be mindful of weight differences and how they affect balance and carry on harnesses or pouches.

Durability and construction

Steel magazines bring proven strength to the table. The H&K MR556’s steel body resists deformation better than many polymer designs when exposed to heavy impacts. In field conditions where gear gets tossed into packs, dropped on hard surfaces, or stacked tightly, steel maintains structural integrity and keeps feed lips aligned for reliable feeding. The 20-round capacity is a compact option that still provides enough rounds for defensive or training scenarios without the bulk of higher-capacity magazines.

Practical edge

For duty use or hard training, the material choice matters. Steel magazines often require less frequent replacement than soft polymers when used rigorously. Routine inspection and proper spring care will keep the H&K MR556 functioning well for years.

Maintenance and storage tips

Maintenance is simple but important. Keep the magazine clean and free from grit and fouling. Lightly wipe the exterior and inspect feed lips for dents. Store magazines unloaded or with a magazine storage solution that relieves spring tension over long periods; this extends spring life and maintains reliable spring force. For steel magazines, a light coating of corrosion inhibitor is smart if you operate in wet or maritime environments.

Use cases and practical scenarios

For sport shooters, the H&K MR556 provides a consistent feed for match or practice sessions where reliability is paramount. For hunters and range users, the 20-round capacity strikes a balance between carrying enough ammunition and keeping weight down. For those who own an MR556 or run AR/M4 platforms at the same time, standardizing on this magazine simplifies gear management.

At a price of $71.09, the H&K MR556 positions itself as a quality spare or replacement magazine. That price reflects a steel construction and the fitment confidence that comes from a magazine designed for the MR556 and compatible with AR-platform rifles.

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Buying considerations and final notes

If you own an MR556 or run multiple AR-type rifles, the H&K MR556 offers a purpose-built steel magazine option with 20-round capacity. Check your local regulations regarding magazine capacities before purchasing. The Heckler & Koch name carries a history of precision engineering, and this magazine is a practical reflection of that lineage. Keep your mags inspected, rotate them into service, and store them properly to maximize service life.

Ready to add a durable, MR556-compatible magazine to your kit? Check current availability and purchase directly from our shop page, which links through to the retailer for checkout.

People Also Ask

What makes this product stand out from competitors?

This product offers superior quality and innovative features that set it apart in the market. Its design focuses on both performance and reliability, making it a top choice for professionals and enthusiasts alike.

Is this product suitable for beginners?

Yes, this product is designed with user-friendly features that make it accessible to beginners while still offering advanced capabilities for experienced users.

What warranty or support is available?

The product comes with comprehensive warranty coverage and excellent customer support to ensure your satisfaction and peace of mind.

How does this compare to similar products in its price range?

This product offers exceptional value for its price point, providing features and quality that typically cost significantly more in comparable alternatives.

What maintenance is required?

Minimal maintenance is required thanks to the product’s durable construction and quality materials. Regular cleaning and occasional inspections will keep it performing optimally.