LU-M455-1604-P : CMMG M4-LEPII Flat Top AR15 M4 Gas Piston Upper - 16" M4 A2 Bird Cage Hider
CMMG M4-LEP-II Gas Piston systems operate cleaner then the direct gas impingement operating systems. With the piston system, the propellant gases that are being diverted at the gas block are now vented at the gas block, instead in the operating system of the upper receiver. Since the fouling from the gas system is not being vented in to the action of your firearm, it stays cooler and cleaner. Our system is designed around the short stroke piston operation. The piston pushes the anti tilt one piece carrier, which unlocks the bolt and allows the piston to return home while the bolt carrier continues to cycle independently. All uppers have been factory head spaced and test fired.

Exception: Does NOT fit Colt Sporter Match H-Bar

The upper is built off of a CMMG standard forged A3 flat top receiver with M4 feed ramps. Chrome plated gas piston is mounted in a solid one piece Steel Gas Block attached with pins. The dedicated, piston specific, anti-tilt bolt carrier is one piece, machined with the piston impingement key (not a bolt on). The one piece carrier uses a CMMG standard Mil-Spec bolt with a 4140 steel barrel, M4 profile, 5.56mm chamber and bore, 1/9 twist ratio and 1/2x28 threaded barrel. Fully finished in CMMG's proprietary WASP surface treatment. The upper includes M4 handguard caps, M4 heat shield lined handguards and an A2 flash hider installed with a crush washer.

The piston gas block has a gas shut off setting for use with a suppressor to allow for maximum noise reduction. You must replace the crush washer with a peel washer if you plan to mount your suppressor on the original flash hider. Fits on any standard Mil-Spec lower receiver.

CMMG 16" M4-LEP II Gas Piston M4 Upper & M4 Barrel Features:
• 16.0" 4140 chrome-moly vanadium steel
• 5.56x45 NATO chamber
• Caliber: .223
• 1/9 Twist Rate
• 1/2x28 RH Muzzle Thread
• Picatinny Rail Gas Block
   
• WASP Coated Chamber & Surface Treatment
• Fits on any standard Mil-Spec lower receiver.
• Not Chrome Lined
• Semi-Auto Bolt Carrier & Charging Handle - Included
• M4 contour barrel profile
• M203 40mm Grenade Launcher Mounting Capability
• M4 feed ramps
• M4 Style Handguards
• 11 degree recessed target crown
• Parkerized Barrel including under the front sight base
• A2 Flash hider installed with Peel washer
• Forged A3 upper receiver are T marked with extended feed ramp cuts (M4 ramps).
• Made In USA