--- title: "HK USA MR556 A4 5.56 NATO Rifle, Black" description: "Black 5.56 NATO rifle with an 11\" configuration, short-stroke gas piston system, adjustable gas regulator, and fully ambidextrous controls." canonical_url: "https://www.kygunco.com/product/hk-usa-mr556-a4-pistol-5.56-223-11-tb-30rd" meta: author: KYGUNCO "og:description": "Black 5.56 NATO rifle with an 11\" configuration, short-stroke gas piston system, adjustable gas regulator, and fully ambidextrous controls." "og:image": "https://cdn.kygunco.com/assets/products/270650/thumbnail.jpg?v=1763583765" "og:image:height": "500" "og:image:width": "500" "og:title": "HK USA MR556 A4 5.56 NATO Rifle, Black" --- > Index of every page on this site: [llms.txt](https://www.kygunco.com/llms.txt) [Home](https://www.kygunco.com/) / [Shooting](https://www.kygunco.com/category/shooting) / [Guns](https://www.kygunco.com/category/shooting/guns) / [Handguns](https://www.kygunco.com/category/shooting/guns/handguns) / [Semi-Auto](https://www.kygunco.com/category/shooting/guns/handguns/semi-auto) / HCK-81001050 ![Main product image](https://static.kygunco.com/cdn-cgi/image/f=auto,w=600/assets/products/270650/main.jpg?v=1763583765) For illustration purposes only, this image may not be an exact representation of the product. # HK USA MR556 A4 5.56 NATO 11" 30rd - Black The HK USA MR556 A4 is a black 5.56 NATO commercial rifle with an 11" configuration and 30rd capacity. Its short-stroke gas piston system helps limit carbon fouling in the action, while the adjustable gas regulator supports suppressed or unsuppressed operation. Fully ambidextrous controls, a slimmer profile, and lighter weight round out the A4 design. 5.0 ** ** ** ** ** [4 reviews](#reviews) $3,749 ![Credova logo](https://www.kygunco.com/brands/credova.svg) As low as **$198.21**/month with ![Credova text logo](https://www.kygunco.com/brands/credova-text.svg) ** Online In Store ** Free Shipping Enjoy delivery to the Lower 48 States at no cost. ** Ships To FFL Dealer Handled by our expert shippers in Bardstown, KY. ** Check Local Restrictions Not sure whether this item can be shipped to your area? Enter your ZIP code for a quick check. Almost gone. Order now before it sells out. Item # 270650 Style HCK-81001050 UPC 642230269439 Condition New Manufacturer [HK USA](https://www.kygunco.com/brand/hk-usa) Model MR556 A4 Round Capacity 30 Caliber 5.56 NATO Action Semi-Auto Barrel Length 11 in The latest update from HK-USA to the commercial variant of the legendary HK416, the MR556 A4 and MR762 A4 represent an enhanced example of no compromise HK performance. Its short-stroke gas piston operating system does not impart hot carbon fouling back into the action, allowing the weapon to run longer, with less maintenance and with less wear on internal components than direct-impingement ARs. Its adjustable gas regulator allows the operator to tune the action specifically for suppressed or unsuppressed operation. Fully ambidextrous controls, lighter weight and a slimmer profile make the A4 easier to operate, manipulate and employ. For those who demand an AR with unmatched capability and uncompromising reliability and durability, the MR A4s remain the top tier solution. Shop with KYGUNCO for the best selection, competitive pricing, and exceptional customer service. Experience the difference that comes with buying from a trusted outdoor retailer with over 20 years of experience in the industry. ** WARNING: This product contains chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm. For more information, go to [www.p65warnings.ca.gov](https://www.p65warnings.ca.gov). 5.0 ** ** ** ** ** 4 reviews ** ** ** ** ** 4 ** ** ** ** ** 0 ** ** ** ** ** 0 ** ** ** ** ** 0 ** ** ** ** ** 0 ## Reviews ** Verified Customer There’s no words for saying, this brand HK greatest of all 8 months ago ** ** ** ** ** ** David Leavenworth, KS Some would say that HK products are overpriced for what you get. I respectfully disagree. You get what you pay for. The fit and finish was perfect. The normal and suppressor settings make a huge difference using my Surefire SOCOM suppressor. Beta males might say this gun is slightly overgassed, but it works. This is the closest you will get to an HK 416, and the accuracy is outstanding. KY Gun CO was amazing. Priced below retail, fast shipping, great communication, and I am a repeat customer. HK is for those who do not wish to compromise. I have the older HK MR 556 and this gun (A4) is lighter and better. 11/22/2025 ** ** ** ** ** ** Lydia Grand Forks, ND No taxes to ND, best prices around for this HK. Fast shipping and zero billing snags. I will get a SP5 from here too! Thank you KYGUNCO! 10/14/2025 ** ** ** ** ** ** Verified Customer Fantastic HK quality. No discernible difference between HKO and HKUSA. The buying process from KYGUNCO was flawless. 1/21/2025 ** ** ** ** ** ## Don't Forget Your Ammo ```json {"@context":"https://schema.org","@graph":[{"@id":"https://www.kygunco.com/#website","@type":"WebSite","description":"Shop KYGUNCO for firearms, ammo, accessories, parts, and outdoor gear at low prices with fast, easy nationwide shipping.","name":"KYGUNCO","url":"https://www.kygunco.com/","publisher":{"@id":"https://www.kygunco.com/#/schema/organization/kygunco"}},{"@id":"https://www.kygunco.com/product/hk-usa-mr556-a4-pistol-5.56-223-11-tb-30rd#webpage","@type":"WebPage","description":"Black 5.56 NATO rifle with an 11\" configuration, short-stroke gas piston system, adjustable gas regulator, and fully ambidextrous controls.","name":"HK USA MR556 A4 5.56 NATO Rifle, 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I respectfully disagree. You get what you pay for. The fit and finish was perfect. The normal and suppressor settings make a huge difference using my Surefire SOCOM suppressor. Beta males might say this gun is slightly overgassed, but it works. This is the closest you will get to an HK 416, and the accuracy is outstanding. KY Gun CO was amazing. Priced below retail, fast shipping, great communication, and I am a repeat customer. HK is for those who do not wish to compromise. I have the older HK MR 556 and this gun (A4) is lighter and better.","reviewRating":{"@type":"Rating","bestRating":5,"worstRating":1,"ratingValue":5},"datePublished":"2025-11-22T17:29:33.2946788+00:00","author":{"@type":"Person","name":"David"},"inLanguage":"en"},{"@type":"Review","name":"Review for HK USA MR556 A4 5.56 NATO 11\" 30rd - Black","reviewBody":"No taxes to ND, best prices around for this HK. Fast shipping and zero billing snags. I will get a SP5 from here too! 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