Heckler & Koch MR556 A4 SBR 5.56 NATO 11" 30-Round Threaded

Heckler & Koch MR556 A4 Features The HK MR556 A4 5.56 NATO operates on a short stroke gas piston system that keeps hot carbon fouling out of the receiver promoting cleaner operation and extended service life. Its cold hammer-forged 11 barrel features a 1/2x28 thread pitch and 1-in-7 twist rate for compatibility with a wide range of projectiles and muzzle devices. The adjustable gas regulator allows the operator to fine-tune performance for suppressed or unsuppressed use. Built as a duty-grade 11 inch 5.56 NATO piston driven SBR it incorporates an HK416 upper receiver fully ambidextrous lower and ambidextrous safety lever for intuitive control from either side. A continuous top rail interface between the upper receiver and M-LOK free float handguard provides a stable optics mounting platform. Additional enhancements include an extended ambidextrous charging handle ambidextrous QD end plate M-LOK interface with integrated ambi QD cups and HK416 slimline collapsible folding stock. Heckler & Koch MR556 A4 Specifications Manufacturer: Heckler & Koch Model: MR556 A4 Type: Short Barreled Rifle Action: Semi-Automatic Caliber: 5.56 NATO Capacity: 30 Barrel Length: 11 Barrel Type: Cold Hammer-Forged Threaded Thread Pitch: 1/2x28 Twist Rate: 1-in-7 Overall Length: 26.5 Operating System: Short Stroke Gas Piston Gas System: Adjustable Gas Regulator Handguard: M-LOK Free Float Rail: Continuous Top Rail Interface Receiver: HK416 Upper Fully Ambidextrous Lower Stock: Collapsible / Folding HK416 Slimline Safety: Ambidextrous Safety Lever Finish: Black Anodized Magazine Included: 1