Daniel Defense M4A1 RIII Upper Receiver Group

The M4A1 RIII Upper Receiver Group is built around a 14.5-inch (368 mm) Cold Hammer Forged M4-profile barrel and is offered as a complete upper assembly for users who require a factory-configured upper. The 368 mm barrel features a 1:7 twist and is chrome-lined, HP/MPI tested, and mil-spec heavy-phosphate coated. This upper utilizes a mid-length gas system and includes a permanently attached, pinned-and-welded extended Daniel Defense flash suppressor.

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 patented 12.5-inch (318 mm) RIS III bolt-up free-float handguard (6-bolt bolt-up system), a pinned low-profile gas block, and a standard M16-profile bolt carrier group — engineered to provide durable, consistent performance from a robust, factory-built upper.

Overview of the M4A1 RIII Upper Receiver Group

• 368 mm Cold Hammer Forged M4-profile barrel with 1:7 twist; chrome-lined, HP/MPI tested and mil-spec heavy-phosphate coated.
• Mid-length direct impingement gas system with pinned low-profile gas block (pistol/short-carbine geometry not used here; mid-length).
• Patented 318 mm RIS III bolt-up free-float handguard (12.5", 6-bolt system) with M-LOK attachment for lightweight modular accessory mounting.
• Pinned and welded extended Daniel Defense flash suppressor, 17-4 PH stainless steel, salt-bath nitride finished (factory-attached).
• Mil-Spec 7075-T6 CNC-machined upper receiver with indexing marks and M4 feed ramps; Type III hard-coat anodized.
• M16-profile bolt carrier group supplied as standard (superfinished, properly staked gas key).
• GRIP-N-RIP charging handle with robust construction for reliable operation.
• Enhanced features include M4 feed ramps, QD sling points on the rail, and an extended flash suppressor for signature reduction.
• Barrel length: 368 mm; handguard length: 318 mm.
• Made in the USA; engineered for factory-level consistency and durability.