Heckler & Koch H&K MR 556 A1 5.56/.223 16.5″ HK416 AR-15 Rifle MLOK 2022
SOLD FOR: $1,825.00
LSB#: WY250421ML007
Make: Heckler & Koch HK
Model: MR556A1
Serial Number: 241-403893
Year of Manufacture: 2022 CC date code.
Caliber: 5.56, .223
Action Type: Semi-Automatic, Proprietary Gas Piston driven, fed by detachable AR15 pattern magazines. This rifle uses a MAGLOCK California Compliant magazine release system with Kingpin.
Markings: The left side of the magazine well is marked “HK MR 556 A1 5.56mm X 45” and “241-403893” behind the bolt catch with bullet diagrams for the ambidextrous safety selector. The right side is marked with “Heckler & Koch Inc. Columbus GA”. The BCG is marked, “HK MR”. The right side of the handguard is marked “GEISSELE AUTOMATICS NORTH WALES PA”. The left side of the upper and the barrel are both marked “HK CD”. The left side of the handguard is marked “MK15 HK416 x 14.5” PN:05-826 PAT: GEISSELE.COM/PATENTS”. The bi-pod adapter is marked with an nsn number and “KNIGHT’S ARMAMENT CO”.
Sights/Optics: This rifle has a full length picatinny rail for the mounting of optics and accessories. Currently mounted is a set of HK flip up back up iron sights.
Barrel Length: 16.5”, 18” with the A1 birdcage flash hider.
Stock Configuration & Condition: The furniture set on the rifle includes a 13.5” Geissele forend with M-lok slots, and picatinny rails. Currently mounted is a Harris bi-pod via a KAC adapter, there is also a KINECT off set pic rail, and a KINECT 3” pic rail. The forend also features two QD cups. The pistol grip is a MAGPUL MOE-K2 rubberized pistol grip. The stock is an HKE1 buttstock with cheek shelves, sling loops and rubber buttpad. The length of pull is 14.25” at full extension. The pistol grip and stock show virtually no signs of wear. The handguard shows some handling wear with minor marks common with this type of matte finish. Overall the furniture set is in Very Good+ to Excellent condition.
Magazine Quantity & Condition: This rifle includes one 10 round Magpul P-mag in Very Good+ condition.
Type of Finish: Anodized Black
Finish Originality: Original
Bore Condition: The bore is bright and the rifling is sharp. There is no erosion in the bore. The feed ramps are smooth and very shiny. This rifle appears unfired outside of factory testing. In this writer’s opinion the bore rates 10/10.
Overall Condition: Like New.
Mechanics: The action functions correctly. We did not fire this rifle. As with all used firearms, a thorough cleaning may be necessary to meet your maintenance requirements.
Box, Paperwork & Accessories: This rifle includes the magazine and attached accessories.
Our Assessment: The HK MR556 is a premium, civilian version of the renowned HK416, built to the same exacting standards by Heckler & Koch. This specific configuration features a 16.5″ cold hammer-forged barrel and a short-stroke gas piston system, which contributes to enhanced reliability and cleaner operation compared to direct impingement systems. The addition of a Geissele handguard improves rigidity, accessory mounting, and heat dissipation, while also offering a slimmer, more ergonomic profile. The rifle is equipped with a Harris bipod, making it ideal for precision or supported shooting scenarios, and the Magpul K2 grip provides a more vertical angle that suits modern shooting stances.
Outfitted with an HK E1 stock for improved shoulder fit and comfort, this MR556 has been made California compliant through the installation of a MAGLOCK system paired with a Kingpin. This setup locks the magazine in place unless the upper and lower receivers are separated, satisfying restrictive state regulations while maintaining the rifle’s functionality. The build strikes a balance between rugged combat-grade construction and refined customization, making it suitable for defensive use, range work, or as a reliable, accurate platform in feature-limited jurisdictions. Please see our high quality photos via the link and best of luck with your bidding!!!-R.L.
