Daniel Defense 18″ Cold Hammer Forged Barrel, 5.56 NATO, 1:7 Twist, S2W Profile, Rifle-Length, with Low Profile Gas Block

Product Description

The Daniel Defense 18″ Cold Hammer Forged Barrel, S2W profile, rifle-length, with low profile gas block is a 5.56mm NATO, 1:7 twist heavy barrel that Daniel Defense lists at 2.89 lbs in this configuration, pairing the company’s Strength-to-Weight contour with the longest and softest gas system on the AR-15 platform.

Rifle-length gas is the reason to buy this configuration over the mid-length version of the same barrel. The port sits further from the chamber than any other AR-15 gas length, so peak port pressure is at its lowest and dwell time at its longest. The bolt unlocks later and more gently, carrier velocity drops, and the whole cycle is smoother and more repeatable.

The low profile gas block configuration lets a long free-float handguard run continuously over the block, which is what a precision 18-inch build wants: an unbroken top rail for a scope and a night vision device, plus plenty of forend for a bipod or a barricade stop. There is no built-in iron front sight in this configuration.

Key Facts

• Brand: Daniel Defense
• Model: 18″ 5.56mm, Rifle Length, 1:7, S2W
• Manufacturer Part Number: 07-116-11044
• Caliber: 5.56mm NATO
• Barrel Length: 18″
• Twist Rate: 1:7
• Barrel Profile: S2W (Daniel Defense proprietary Heavy Barrel)
• Gas System: Rifle Length
• Manufacturing Process: Cold Hammer Forged
• Material: 4150 Chrome Moly Vanadium (CMV) steel
• Bore Finish: Chrome lined
• Exterior Finish: Mil-Spec Heavy Phosphate
• Muzzle Thread: 1/2×28 TPI
• Diameter at Gas Port: .750″
• Barrel Extension: A4
• Barrel Weight (with low profile gas block): 2.89 lbs
• Barrel Weight (stripped): 2.81 lbs
• Barrel Configuration: With low profile gas block

Rifle-length gas: what it buys and what it costs

The benefit is the softest, most consistent cycle available on the platform, with the lowest chamber-to-port pressure and the longest dwell. The cost is that a rifle-length gas system needs a rifle-length gas tube, which is not interchangeable with carbine or mid-length tubes, and it places the gas block a long way forward.

Fitment and legal status

This barrel installs in any AR-15 or M16-pattern upper on its A4 extension. Source a rifle-length gas tube and a barrel nut matched to your handguard system; Daniel Defense rails use their own dedicated barrel nuts rather than the mil-spec nut. Daniel Defense states its gas blocks follow military specifications for dimensions, and the .750-inch journal here is the standard AR-15 size.

Choose a long free-float tube from our rails and handguards, add glass from our optics range, or compare the rest of our Daniel Defense barrels.

Ordering from Western Sport in Roanoke, TX

Western Sport, in Roanoke, Texas, has held a licensed FFL and SOT since 2007 and is a Daniel Defense master dealer with a gunsmith on site. Heavy precision barrels reward a careful install and a verified headspace, and that is work we do here: call 817-393-4000.

Frequently Asked Questions

Q: How much does this barrel weigh with the low profile gas block?

A: Daniel Defense lists 2.89 lbs in the low profile gas block configuration, and 2.81 lbs for the stripped barrel. That covers barrel and gas block only, so add a rifle-length gas tube, barrel nut, handguard, muzzle device and optic mount to estimate the finished rifle.

Q: What gas tube length does a rifle-length system take?

A: A rifle-length gas tube. It is the longest of the three common AR-15 gas tube lengths and it is not interchangeable with carbine or mid-length tubes. Fitting the wrong length is the most common reason a rifle-gas build fails to cycle, so order the tube specifically rather than relying on a parts kit.

Q: Is rifle-length gas better than mid-length on an 18″ barrel?

A: For precision shooting, generally yes. Rifle-length puts the port furthest from the chamber, giving the lowest port pressure and longest dwell, which makes the cycle softer and more repeatable. Mid-length is firmer, slightly lighter at 2.65 lbs stripped for this profile, and uses more widely stocked parts.

Q: Will a long free-float handguard fit over the gas block?

A: Yes, that is the purpose of the low profile gas block configuration. Because rifle-length gas puts the block well forward, you will want a long handguard to cover it, typically in the 15-inch class on an 18-inch barrel. Check the rail’s internal clearance against your specific gas block before ordering.

Q: Does the chrome lining hurt accuracy on a heavy barrel?

A: Chrome lining adds a plated layer inside the bore and is generally considered a small theoretical compromise against an unlined match bore, in exchange for corrosion resistance and easier cleaning. If an unlined precision bore is what you want, Daniel Defense’s 18″ MK12 barrel uses a stainless blend with no chrome lining instead.

Q: Is a muzzle device required on an 18″ barrel?

A: No. Eighteen inches is comfortably over the federal 16-inch minimum for a rifle, so nothing needs to be permanently attached and the 1/2×28 threads stay free. Fit a brake, flash hider or suppressor mount as you prefer and change it whenever you like without gunsmith work.

Additional information