Daniel Defense RIII 5.56 NATO Rifle & RIS III Rail

There’s a fair amount of interest in the guns of the U.S. Special Operations community due to the selection process associated with them. These guns go through a ton of abuse before they are ever fielded, and then they must perform under austere circumstances for years if they expect to remain. This makes for some compelling research and development for the commercial consumer because none of us have the time or money to beat on guns like the they do.

I like to keep track of what’s serving in this part of our military because it speaks highly of the companies that build the products for the market. Daniel Defense is one of those companies, and they’ve been making AR-15 forends — i.e., “rails” — for almost 20 years.

The rifle issued to U.S. Army Special Operations at the turn of the century was a modified M4 carbine. It featured a quad-rail handguard that replaced the factory plastic handguards. This meant that everything touching or mounted to the handguard — light, laser, foregrip, etc. — might as well have been mounted directly to the barrel. The rifle’s accuracy suffered as a result.

In 2005, the United States Army Special Operations Command (USASOC) decided to upgrade their issued M4A1 and picked the Daniel Defense RIS II. This resulted in some significant improvements. The first was that it divorced the barrel from the forend (and everything mounted to it). The barrel became “free floating,” and accuracy improved while also becoming more consistent. Next, the handguard was increased in length from 71/2 inches to 91/2 inches on carbines with a 10.3-inch barrel, and 12 inches on the 141/2-inch barreled guns. That additional real estate mattered a lot when shooting from field positions with lights and lasers mounted. Finally, the RIS II allowed the military to attach a grenade launcher to the handguard instead of the barrel. In what should be a surprise to no one, this improved accuracy significantly on those as well.

Daniel Defense also saw the adoption of its barrels within SOCOM as part of a product improvement program. In 2015, USASOC decided it needed to further update its rifles with a better barrel. The M855A1 Enhanced Performance Round (EPR) had been out for a few years, and it was a higher-pressure load than anything previously fielded. The additional pressure was hard on the barrel’s rifling and SOCOM saw barrel life drop precipitously. They decided to adopt Daniel Defense’s hammer-forged and chrome-lined 141/2-inch barrel with mid-length gas system. (I remember being shocked that USASOC took AR-15 barrels seriously enough to come up with the right answer. Later, I came to find out that a couple of friends of mine were responsible for that project, so I shouldn’t have been surprised.)

Hammer-forging the barrel work-hardens the bore and makes it more resistant to wear than cut- or button-rifled barrels. The military previously used button-rifled barrels, so the new hammer-forging process gave them a measurable increase in barrel life. Lengthening the gas system allowed the bolt to stay closed longer and let chamber pressure drop before unlocking the bolt to extract the fired case. The M855A1 quickly earned a reputation for shearing bolt lugs when the bolt twisted to unlock for having a higher chamber pressure. Lengthening the gas system provided some much-needed relief. USASOC liked Daniel Defense’s barrel so much, they continue to use it today.

All of that tribal knowledge has made its way to the newest rifle from Daniel Defense: The RIII. This rifle features a forend that attaches to the rifle in the exact same manner as the RIS II, but it replaces the long sections of Picatinny rail on the RIS II with smooth, hand-friendly sections of M-Lok. M-Lok is SOCOM’s attachment method, so it’s no surprise to see it on the RIS III ($476).

The barrel on the new RIII rifle is still the hammer-forged version with mid-length gas system that USASOC loves so much, too. AR-15s barrels between 141/2- and 16-inches long are at their best with this gas system because of the lower residual chamber pressure when the bolt unlocks, which leads to longer bolt life.

The fresh handguard is pretty sweet, but the ambidextrous features of the RIII give this AR-15 some additional capability not normally found on these platforms. Making an AR-15 ambidextrous might not sound like a big deal to most of the world because we’re right-handed. However, a regular right-handed AR-15 doesn’t allow the shooter to pull the charging handle to the rear and lock the bolt back without removing the rifle from the shoulder. This is a critical step in clearing malfunctions. The way the AR-15 was designed requires the shooter to pull the charging handle rearward with the right hand while activating the bolt catch with the left hand. Daniel Defense’s new RIII carbine features a lower receiver with both bolt catch and bolt release — not the same thing — on both sides of the rifle. The shooter can now keep the rifle shouldered while performing any rifle manipulation that’s needed. The rifle components required to clear malfunctions and reload with a fresh magazine are now present on both sides of the receiver.

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Where most manufacturers of ambidextrous magazine releases go wrong is that they try and use a regular AR-15 lower receiver and then hang some claptrap off the backside of the regular magazine release to make it ambi. The problem with that approach is that the new fancy mag release now protrudes away from the rifle; when slung muzzle down across the body, that protrusion is the first thing that contacts the shooter’s body. This can lead to ejecting the magazine at the most inopportune moment.

Daniel Defense was smarter than that and uses a lower receiver of its own design. The receiver has a protective fence (similar to the one found around the magazine release) on the right side of the rifle. The raised aluminum fence that’s molded into the lower receiver prevents accidental manipulation of the release and keeps the magazine seated in the rifle until the shooter chooses to dump it. Making this lower receiver was undoubtedly inconvenient for Daniel Defense. It’s a small detail that will go unnoticed by many, but including a protective fence is the only way to make an ambidextrous magazine release function reliably and correctly. I applaud the integrity of the engineers who made the lower receiver this way.

Daniel Defense has been making premium AR-15 components for a long time, and most of those components have served our country with distinction. The new RIII rifle takes all of those proven elements and paired them with some well-designed and relevant features to create the most capable AR-15 — and rail — in Daniel Defense’s 22-year history.

Daniel Defense DD4 RIII

• Type: Direct impingement, semiautomatic
• Cartridge: 5.56 NATO
• Capacity: 30 rds.
• Barrel: 16 in., 1:7-in. twist
• Overall length: 32.5 in. (collapsed); 36 in. (extended)
• Weight: 6 lbs., 7 oz.
• Stock: Daniel Defense, collapsible 
• Grip: Daniel Defense 
• Length of pull: 10.5 in. (collapsed); 13.5 in. (extended)
• Finish: Type III hardcoat anodized
• Sights: None
• Safety: Two-position selector
• MSRP: $2,324
• Manufacturer: Daniel Defense, danieldefense.com, 866-554-4867