The HK MR762 A4 represents the most advanced commercial evolution of the battle-proven Heckler & Koch HK417 architecture. Introduced as a major generational upgrade over the older A1 variant, the A4 series introduces highly requested enhancements, including a modernized adjustable gas regulator for suppressed shooting and fully ambidextrous lower receiver controls. - VERY GOOD CONDITION - ORIGINAL RANGE BAG - ONE 20-RD MAGAZINE Action Type: Short-stroke gas piston semi-automatic. Caliber: 7.62x51mm NATO / .308 Winchester. Gas Block: Two-position adjustable gas regulator (Normal / Suppressed settings). Barrel Lengths: 16.5 inches Barrel Construction: Cold hammer-forged, cannon-grade steel with a 1:11" right-hand twist rate. Muzzle Thread: 5/8x24 TPI (standard American threading, unlike older HK metric threads). Lower Controls: Fully ambidextrous magazine release, bolt catch/release, and 45-degree safety selector. Handguard: Lightweight, free-floating M-LOK handguard system. Trigger Group: Proprietary two-stage match trigger (approx. 4.5 lbs pull weight). Magazine Compatibility: Uses proprietary HK transparent polymer magazines (not compatible with SR-25/PMAG patterns). Weight (Unloaded): 9.8 lbs Receiver Material: Forged aluminum upper