Daniel Defense DD4 M4A1 RIII Rifle, 5.56 NATO, 14.5″ Barrel, California Compliant

Product Description

The Daniel Defense DD4 M4A1 RIII Rifle in this configuration is a semi-automatic 5.56 NATO rifle with a 14.5" M4 profile barrel, 1:7 twist, carbine-length gas system, a RIS III 12.5 M-LOK rail and an extended Daniel Defense flash suppressor pinned and welded, built by Daniel Defense as a California Compliant SKU.

This is the duty-carbine configuration. A 14.5" barrel with a permanently attached muzzle device measures past 16 inches as a unit, which is what keeps it a rifle instead of an NFA item: pinning and welding makes the flash suppressor part of the barrel. You get the balance and handling of a 14.5" carbine with none of the paperwork a short-barrelled rifle demands.

The M4 profile and carbine gas system behave predictably at this length: a slightly sharper impulse than a mid-length, faster lock time, and reliability across a wide range of ammunition. The RIII generation replaces the original M4A1’s RIS II quad rail with a 12.5-inch RIS III M-LOK rail, dropping weight while keeping the M203 mounting provision, and the fully ambidextrous lower lets either hand run the bolt catch, selector and magazine release.

Key Facts

• Brand / Model: Daniel Defense DD4 M4A1 RIII
• Manufacturer Part Number: 02-191-04238-055
• Legal category: Rifle  |  Class: California Compliant
• Action: Semi-automatic  |  Caliber: 5.56mm NATO
• Barrel: 14.5", M4 profile, 1:7 twist
• Barrel material: Chrome Moly Vanadium steel, cold hammer forged
• Barrel finish: Chrome lined, Mil-Spec heavy phosphate coated, HP/MPI tested
• Gas system: Carbine length
• Muzzle device: Extended Daniel Defense flash suppressor, pinned and welded (permanently attached)
• Muzzle thread: 1/2 x 28 TPI
• Rail: Daniel Defense RIS III 12.5, M-LOK attachment
• Receivers: 7075-T6 aluminium, Type III hard coat anodized; proprietary lower with enhanced flared magazine well, ambidextrous controls and rear receiver QD point; Mil-Spec upper with M4 feed ramps
• Receiver extension: 6 position Mil-Spec 7075-T6 aluminium
• Bolt carrier group: M16 profile, Mil-Spec MP tested, chrome lined, staked gas key
• Trigger: Mil-Spec
• Overall length: 31 1/2" – 34 3/4" (with muzzle device)
• Furniture: Daniel Defense buttstock and pistol grip, soft touch overmolding

Pinned and welded: what it means for you

The extended flash suppressor on this rifle is not removable. It is pinned through and welded to the barrel shoulder so barrel and device are a single permanent unit over 16 inches, which is why this ships as a rifle. Practically, that means no muzzle device swaps and no direct-thread suppressor mounting without a gunsmith’s involvement — and no NFA paperwork for the gun itself. Our gunsmith is on site if you have questions.

California Compliant configuration

Daniel Defense builds this SKU as a California Compliant M4A1 RIII. Compliance rules change over time and are applied differently in different counties and cities, so nothing here should be read as a statement that this rifle is legal in any particular place. Confirm the current requirements for your own jurisdiction before ordering, then call 817-393-4000 and we will go over the exact compliance details on this SKU. Cross-shop the Daniel Defense rifle line-up and our optics and mounts while you decide.

Ordering from Western Sport in Roanoke, TX

A Daniel Defense master dealer since 2007, Western Sport is a licensed FFL and SOT in Roanoke, Texas with a gunsmith on site. Like every firearm, this DD4 M4A1 RIII must be transferred through a licensed FFL — ours or one near you. Call 817-393-4000 and we will handle it.

Frequently Asked Questions

Q: Why is a 14.5-inch barrel not a short-barrelled rifle?

A: Because the extended Daniel Defense flash suppressor is pinned and welded to it. Once a muzzle device is permanently attached, barrel and device are measured as one unit, and this one exceeds 16 inches. That keeps the rifle outside the NFA short-barrelled rifle category, so it transfers like any other rifle.

Q: Can the pinned and welded flash suppressor be removed?

A: Not without gunsmithing. It is pinned through and welded to the barrel shoulder, which is what makes the rifle legal at this barrel length. Removing it would change the firearm’s legal status, so we do not advise it. Our gunsmith in Roanoke can answer questions about this configuration.

Q: How does the carbine gas system on this 14.5-inch barrel feel compared with a mid-length?

A: A little sharper. The gas port sits closer to the chamber, so port pressure is higher and the carrier unlocks sooner, giving a quicker, firmer impulse. It is also the specification the military uses at this barrel length, and it is reliably tolerant of varied ammunition.

Q: What rail does the DD4 M4A1 RIII use?

A: A Daniel Defense RIS III 12.5 with M-LOK attachment. It replaces the RIS II Picatinny quad rail used on the original M4A1, saving weight while keeping the M203 mounting provision and leaving an uninterrupted top rail for optics and night vision.

Q: Is this DD4 M4A1 RIII legal in California?

A: We cannot make that statement. Daniel Defense builds this SKU as a California Compliant configuration, but the requirements change and are enforced differently by locality. Confirm current rules for your own city and county before ordering, and call 817-393-4000 so we can go over the exact compliance features on this SKU with you.

Q: How is the transfer handled on this compliant rifle?

A: This is a serialized firearm and must go through a licensed FFL. Western Sport in Roanoke, Texas is a licensed FFL and SOT and can complete the transfer at our counter, or ship to an FFL closer to you. Call 817-393-4000 and we will arrange whichever suits you.

Additional information