Heckler and Koch MR556 A4 5.56 16.5 Barrel 10-Rounds CA Compliant

HK MR556 A4 Features The MR556 A4 rifle is chambered in 5.56x45mm with a 10+1 capacity and a 16.5-inch 1:7 twist threaded steel barrel with 1/2x28 threading built on HK s short-stroke gas piston operating system that does not impart hot carbon fouling back into the action for cleaner longer-running performance with less maintenance than direct-impingement AR platforms. An adjustable gas regulator allows precise tuning for suppressed or unsuppressed operation making the MR556 A4 a versatile platform for shooters who run a suppressor alongside standard muzzle configurations. The fully ambidextrous lower receiver with ambidextrous safety lever charging handle and controls accommodates both right- and left-handed shooters without modification or aftermarket components. The HK416 upper receiver brings proven military-grade dimensional tolerances and construction quality to the MR556 A4 platform paired with an M-LOK handguard that provides a lightweight flexible accessory interface for lights lasers grips and other tactical attachments. A Picatinny top rail provides a standardized optics mounting surface across the full receiver length for red dots scopes and magnifiers suited to the 5.56x45mm s effective range. The lighter weight and slimmer profile of the A4 configuration improve handling manipulation and employment across a wide range of shooting positions and operational scenarios. HK engineered the MR556 A4 as a civilian-legal counterpart to the HK416 that brings the military platform s piston-driven reliability and ambidextrous ergonomics to the American sporting rifle market in a California compliant configuration. The combination of a short-stroke piston system adjustable gas regulator HK416 upper and fully ambidextrous controls makes the MR556 A4 one of the most feature-complete and durable AR-pattern rifles available at any price point. For serious AR shooters who want HK s military-proven piston system and build quality in a compliant fully ambidextrous platform the MR556 A4 is a definitive choice. HK MR556 A4 Specifications Manufacturer: HK Model: MR556 A4 Series: A4 Caliber: 5.56x45mm Capacity: 10+1 Action: Semi-Auto Operating System: Short-Stroke Gas Piston Gas Regulator: Adjustable Barrel Length: 16.5 Barrel Material: Steel Barrel Finish: Black Barrel Description: Threaded Thread Pattern: 1/2x28 Twist Rate: 1:7 Grooves: 6 Upper Receiver: HK416 Receiver Finish: Black Receiver Description: Picatinny Rail Lower Receiver: Fully Ambidextrous Handguard: M-LOK Stock: Black Polymer Grip: Black Polymer Safety: Ambidextrous Selector Switch Hand: Ambidextrous Height: 7.50 Width: 3.07 Weight: 7.67 lbs Magazines Included: 1 x 10-round Compliance: California Compliant