Description
The Daniel Defense DD4 FDE RIS II Barreled Upper Receiver provides a fully assembled, mil-specification upper solution for AR-15 builds requiring combat-proven components, SOCOM-derived rail geometry, and a finish optimized for field identification and personalization.
The Daniel Defense DD4 RIS II is a 14.5" barreled upper receiver assembly chambered in 5.56mm NATO, configured around the Daniel Defense RIS II free-float quad rail handguard on a mil-spec 7075-T6 aluminum upper receiver platform.
The RIS II handguard was developed in direct response to requirements established by United States Special Operations Command for the SOCOM II program. Its patented Bolt-Up barrel nut system produces a two-piece rigid structure that resists deflection under accessory load and sustained fire, maintaining point of impact consistency where lesser rail systems introduce variance.
The lower rail section is removable for compatibility with the M203 grenade launcher, a design consideration that reflects the operational origins of this platform. The 14.5" cold hammer forged chrome moly vanadium barrel is chrome lined for sustained round count durability and phosphate coated to mil-specification, with each unit proof tested and magnetic particle inspected prior to leaving the factory. A pinned and welded Daniel Defense extended flash suppressor in 17-4 PH stainless steel with salt bath nitride finish brings the assembly to a legal 16" overall barrel length, eliminating the requirement for an NFA short-barreled rifle registration. BCG and charging handle are not included, allowing the end user to specify those components independently.
Features:
- Caliber: 5.56mm NATO
- Barrel Length: 14.5" (pinned and welded to 16" legal length)
- Barrel Profile: M4
- Barrel Material: Chrome moly vanadium steel, cold hammer forged
- Barrel Finish: Chrome lined, mil-spec heavy phosphate coated
- Barrel Testing: HP/MPI tested
- Twist Rate: 1:7
- Gas System: Mid-length, direct impingement
- Gas Block: Pinned low profile, 4140 hardened steel, mil-spec heavy phosphate coated
- Upper Receiver: Mil-spec 7075-T6 aluminum, CNC machined,
- Type III hard coat anodized
- Feed Ramps: M4
- Handguard: Daniel Defense RIS II free-float quad rail
- Handguard Mounting: Patented Bolt-Up barrel nut system
- Muzzle Device: Daniel Defense extended flash suppressor, pinned and welded
- Muzzle Thread: 1/2x28 TPI
- Finish: Flat Dark Earth (FDE)
- BCG and Charging Handle: Not included
Compatible with all mil-spec AR-15 lower receivers, this upper receiver conforms to standard mil-spec dimensional tolerances, accepting any compatible BCG and charging handle selected by the end user.
7075-T6 aluminum with Type III hard coat anodizing provides the upper receiver with corrosion resistance and surface hardness consistent with military specification requirements. Cold hammer forging optimizes the barrel steel grain structure for wear resistance and sustained accuracy under extended use conditions.
Applicable to carbine builds requiring a proven short-barrel profile within a non-NFA configuration. The quad rail system accommodates full-length accessory integration including lights, lasers, grips, and optic mounts across all four rail faces without the use of adapters.
Specifications
Barrel Contour: M4
Barrel Length: 14.5
Barrel Lining: Chrome
Barrel Material: 4150 Chrome Moly Steel
Brand: Daniel Defense
Caliber Gauge: 5.56 NATO
Color: Flat Dark Earth
Finish: Hardcoat Anodized
Gas System Length: Mid-Length
Gas System Type: Direct Impingement
Handguard: 12.25 in Freefloat Rail
Muzzle Device: Daniel Defense Flash Suppresor
Platform: AR-15
Thread Pattern: 1/2 X 28
Twist Rate: 1:7
SKU: DD-PA-EXCLUSIVE-14-5-556-FDE
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