MK18 RIII Upper Receiver Group

The MK18 RIII Upper Receiver Group is built around a 10.3-inch (262 mm) Cold Hammer Forged M4-profile barrel and features a Daniel Defense Flash Suppressor, a GRIP-N-RIP charging handle, and a carbine-length gas system. The upper uses a patented 9.5-inch (241 mm) RIS III bolt-up free-float handguard with M-LOK attachment for lightweight modular accessory mounting. Note: this listing is for the upper receiver group only — not a complete rifle.

Daniel Defense manufactures components and complete assemblies to exacting standards. This upper pairs a Mil-Spec CNC-machined 7075-T6 aluminum upper receiver (Type III hard-coat anodized) with a chrome-lined, HP/MPI-tested Cold Hammer Forged barrel, a pinned low-profile gas block, and an M16-profile bolt carrier group — engineered for durable, consistent performance from a factory-built upper.

Overview of the MK18 RIII Upper Receiver Group

• 262 mm Cold Hammer Forged M4-profile barrel with 1:7 twist; chrome-lined and HP/MPI tested.
• Carbine-length direct impingement gas system with pinned low-profile gas block for reliable cycling.
• Patented 241 mm RIS III bolt-up free-float handguard (9.5", 6-bolt system) with M-LOK attachment for lightweight modularity.
• Muzzle device: Daniel Defense Flash Suppressor, 17-4 PH stainless steel, salt-bath nitride finished.
• M16-profile bolt carrier group supplied as standard (mil-spec MP tested, chrome-lined, properly staked gas key).
• GRIP-N-RIP charging handle and robust ergonomics for reliable handling.
• Mil-Spec 7075-T6 CNC-machined upper receiver with indexing marks and M4 feed ramps; Type III hard-coat anodized.
• Weight: 1590 g; barrel length: 262 mm; handguard length: 241 mm.
• Made in the USA; engineered for factory-level consistency and durability.