The Daniel Defense M4A1 features the M4A1 RIS II which has been in use by US Special Operations Command (SOCOM) for the SOPMOD II Weapons System since 2005. The M4A1 features a 14.5in Cold Hammer Forged M4 Profile barrel with a permanently attached Daniel Defense Flash Suppressor. This rifle also comes with the newly designed rugged and comfortable Daniel Defense Buttstock and Pistol Grip. – MATERIALS & CONSTRUCTION – LOWER RECEIVER: Mil-Spec with Enhanced Flared Magazine Well and Rear Receiver QD Swivel Attachment Point. CNC Machined of 7075-T6 Aluminum Type III Hard Coat Anodized – UPPER RECEIVER: Mil-Spec with Indexing Marks and M4 Feed Ramps. CNC Machined of 7075-T6 Aluminum Type III Hard Coat Anodized – BARREL: Chrome Moly Vanadium Steel Cold Hammer Forged 1:7 Twist 14.5 M4 Profile Chrome Lined Mil-Spec Heavy Phosphate Coated and HP/MPI Tested – GAS SYSTEM: Pinned Low Profile Gas Block CNC Machined of 4140 hardened steel with Mil-Spec Heavy Phosphate Coating Carbine length Direct Impingement – MUZZLE DEVICE: Pinned and Welded Daniel Defense Flash Suppressor 17-4 PH Stainless Steel Salt Bath Nitride Finished – BOLT CARRIER GROUP: M16 Profile Mil-Spec MP Tested Chrome Lined Properly Staked Gas Key – BUFFER: H Buffer – SIGHTS: Sold Separately – HANDGUARD: Daniel Defense M4A1 Rail Interface System (RIS) II CNC Machined of 6061-T6 Aluminum Type III Hard Coat Anodized FDE – RECEIVER EXTENSION: 6 Position Mil-Spec 7075-T6 Aluminum – BUTTSTOCK: Daniel Defense Buttstock Glass Filled Polymer with Soft Touch Overmolding – PISTOL GRIP: Daniel Defense Pistol Grip Glass Filled Polymer with Soft Touch Overmolding – RAIL PANELS: Daniel Defense Rail Panels made from Santoprene heat resistant to 300° F. – Made in the USA! – Caliber: 5.56mm NATO – Muzzle Thread: 1/2×28 TPI (Threads Per Inch) – Gas System: Carbine – Barrel Length: 14.5 – Profile: M4 – Product Weight: 6.74 lbs – Length: 31 1/2in to 34 3/4in – Magazine: DD Magazine – Case: Daniel Defense Full-Latch Impact Plastic Case