The DD4 RIII Upper Receiver Group offers the longest barrel length of the RIII family and is perfect for popular shooting sports and for tactical defensive applications. Built around a 16 inch Cold Hammer Forged Government Profile barrel, its mid-length gas system is known to have a smoother recoil impulse. A 12.5 inch lightweight RIS III rail-modeled after the revolutionary RIS II two-piece handguard developed for SOCOM-free-floats the barrel and features M-LOK attachment for lighter weight. It has our ambidextrous Grip-N-Rip Charging Handle and ships with an M16 Profile bolt carrier group.Features:UPPER RECEIVER: Mil-Spec with Indexing Marks and M4 Feed Ramps. CNC Machined of 7075-T6 Aluminum, Type III Hard Coat AnodizedBARREL: Chrome Moly Vanadium Steel, Cold Hammer Forged, 1:7 Twist, 16" Government Profile, Mid-length Gas System, Chrome Lined, Mil-Spec Heavy Phosphate Coated, and HP/MPI TestedGAS SYSTEM: Pinned Low Profile Gas Block CNC Machined of 4140 Hardened Steel and Mil-Spec Heavy Phosphate Coating, Mid-length, Direct ImpingementMUZZLE DEVICE: Daniel Defense Flash Suppressor, 17-4 PH Stainless Steel, Salt Bath Nitride FinishedBOLT CARRIER GROUP: M16 Profile, Mil-Spec MP Tested, Chrome Lined, Properly Staked Gas KeyHANDGUARD: RIS III 12.5, Patented 6-Bolt Bolt-Up System, CNC Machined of 6061-T6 Aluminum, Black or FDE Type III Hard Coat AnodizedCHARGING HANDLE: GRIP-N-RIP Charging Handle, Body CNC Machined of 7075-T6 Aluminum, Handles & Latch CNC Machined of 6061-T6 Aluminum, Heavy Duty Stainless Steel Roll Pins, Type III Hard Coat AnodizedSpecifications:Barrel Material: 4150 Chrome Moly VanadiumBarrel Type: Cold Hammer ForgedBarrel Profile: GovernmentRifling Twist: 1:7"Gas System Length: Mid-lengthMuzzle Device: Flash SuppressorWeight: 4.35 LBSRail System: RIS III 12.5 (M-LOK)