Primary Weapons Systems MK116 MOD 2-M Complete Upper Features The Primary Weapons Systems MK116 MOD 2-M Complete Upper is built around the company s long stroke piston operating system with a 3-setting adjustable gas system an operating method that keeps combustion gases out of the receiver compared to traditional direct impingement designs. That piston system reduces the heat and fouling transferred back into the action which translates to a cleaner-running rifle and less frequent maintenance between range sessions. The 16.1 inch 41V50 steel barrel is cut with a 1 in 10 twist rate matched to stabilize the bullet weights commonly loaded in 7.62x39 and achieves a muzzle velocity of roughly 2374 feet per second. A Triad 30 muzzle device caps the barrel managing flash and recoil for faster follow-up shots in a caliber known for stouter recoil impulse than 5.56. The upper receiver itself is a proprietary PWS piston design forged from 7075-T651 aluminum and hard coat anodized per Mil-8625 Type III Class 2 standards giving it a durability level well above standard commercial anodizing. A 15 inch PWS PicLok handguard offers patent pending technology that lets the shooter mount either Picatinny rail sections or M-LOK accessories directly to the forend adapting to whatever accessory ecosystem the builder prefers. A Radian Raptor ambidextrous charging handle ships installed giving smooth reliable manipulation from either side of the rifle regardless of shooting position. For AR-15 builders looking to add a piston-driven 7.62x39 upper with premium components this MK116 MOD 2-M delivers PWS s signature engineering in a caliber built for close to medium range power. Primary Weapons Systems MK116 MOD 2-M Complete Upper Specifications Manufacturer: Primary Weapons Systems Model: MK116 MOD 2-M Complete Upper Caliber: 7.62 X 39 Barrel Length: 16.1 Barrel Material: 41V50 Steel Twist Rate: 1:10 Muzzle Device: Triad 30 Muzzle Velocity: 2374 ft/sec Color: Black Finish: Anodized Receiver Material: Aluminum Handguard: 15 PWS PicLok M-LOK/Picatinny Charging Handle: Radian Raptor Ambidextrous Operating System: PWS Long Stroke Piston Gas System Length: Carbine Weight: 4.8 lbs Available At: GrabAGun