Primary Weapons Systems MK116 Compound Features The Primary Weapons Systems MK116 Compound runs on PWS s long-stroke piston operating system keeping combustion gases out of the receiver entirely and resulting in a cleaner-running action that requires less frequent maintenance than a comparable direct-impingement AR-15. A 3-setting adjustable gas regulator lets shooters fine-tune the system s cycling force to match different ammunition loads or a suppressor a meaningful advantage for a piston rifle expected to run in varied conditions. The forged and anodized T6 7075 upper receiver houses the proprietary piston upper and the ambidextrous MK1 MOD 2-M lower is hard-coat anodized per Mil-8625 Type III Class 2 for long-term durability. PWS ships the MK116 Compound with a 15.05 inch M-LOK handguard for accessory mounting a Radian Raptor ambidextrous charging handle for fast positive manipulation from either side and an enhanced buffer tube with a ratchet-lock castle nut and built-in QD sling mount. Bravo Company USA furniture rounds out the ergonomics package giving the rifle a proven duty-grade buttstock and pistol grip right out of the box. For AR shooters who want a piston-driven .223 Wylde rifle with the reliability and reduced maintenance PWS is known for the MK116 Compound delivers a complete ready-to-run package. Primary Weapons Systems MK116 Compound Specifications Brand: Primary Weapons Systems Model: MK116 Compound Caliber: .223 Wylde Capacity: 30 Barrel Length: 16.1 Operating System: PWS Long Stroke Piston Gas System: Mid-Length 3-Setting Adjustable Twist Rate: 1:8 Handguard: PWS M-LOK 15.05 Charging Handle: Radian Raptor Ambidextrous Muzzle Device: PWS FSC 556 Finish: Anodized Available At: GrabAGun