--- title: "HK USA MR556 A4 5.56 Rifle, 30rd Black" description: "Black HK USA MR556 A4 rifle with a 16.5\" barrel, 30rd capacity, short-stroke gas piston system, adjustable gas regulator, and ambidextrous controls." canonical_url: "https://www.kygunco.com/product/hk-usa-mr556-223-5.56-16.5-30rd-black" meta: author: KYGUNCO "og:description": "Black HK USA MR556 A4 rifle with a 16.5\" barrel, 30rd capacity, short-stroke gas piston system, adjustable gas regulator, and ambidextrous controls." "og:image": "https://cdn.kygunco.com/assets/products/270578/thumbnail.jpg?v=1732882161" "og:image:height": "500" "og:image:width": "500" "og:title": "HK USA MR556 A4 5.56 Rifle, 30rd 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) / [Rifles](https://www.kygunco.com/category/shooting/guns/rifles) / [Semi-Auto](https://www.kygunco.com/category/shooting/guns/rifles/semi-auto) / HCK-81000827 ![Main product image](https://static.kygunco.com/cdn-cgi/image/f=auto,w=600/assets/products/270578/main.jpg?v=1732882161) For illustration purposes only, this image may not be an exact representation of the product. # HK USA MR556 223/5.56 16.5" 30rd - Black The HK USA MR556 A4 is a black semi-automatic rifle chambered in .223 Remington/5.56 NATO with a 16.5" barrel and 30rd capacity. Its short-stroke gas piston system helps reduce carbon fouling in the action, while the adjustable gas regulator supports suppressed or unsuppressed operation. Fully ambidextrous controls add versatility. $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. Item # 270578 Style HCK-81000827 UPC 642230269408 Condition New Manufacturer [HK USA](https://www.kygunco.com/brand/hk-usa) Model MR556 Round Capacity 30 Caliber 5.56 NATO, 223 Rem Action Semi-Auto Barrel Length 16.5 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). 0.0 ** ** ** ** ** 0 reviews ** ** ** ** ** 0 ** ** ** ** ** 0 ** ** ** ** ** 0 ** ** ** ** ** 0 ** ** ** ** ** 0 ## 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-mr556-223-5.56-16.5-30rd-black#webpage","@type":"WebPage","description":"Black HK USA MR556 A4 rifle with a 16.5\" barrel, 30rd capacity, short-stroke gas piston system, adjustable gas regulator, and ambidextrous controls.","name":"HK USA MR556 A4 5.56 Rifle, 30rd 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