Daniel Defense 18″ Cold Hammer Forged Barrel, 5.56 NATO, 1:7 Twist, S2W Profile, Mid-Length

Product Description

The Daniel Defense 18″ Cold Hammer Forged Barrel, S2W profile, mid-length in this retail assembly is the stripped configuration of the company’s Strength-to-Weight heavy barrel in 5.56mm NATO, 1:7 twist, weighing 2.65 lbs with no gas block fitted.

S2W is Daniel Defense’s proprietary heavy barrel contour, described by the company as its Strength to Weight profile. It carries substantially more steel than the Government or Lightweight profiles, and at 2.65 lbs this barrel weighs nearly a pound more than the 16″ Lightweight barrel.

Eighteen inches with a mid-length gas system is an unusual and interesting combination. Mid-length puts the gas port closer to the chamber than a rifle-length system would at this barrel length, which means a shorter section of barrel forward of the block and a slightly firmer impulse than rifle gas gives, but also a shorter overall handguard requirement and compatibility with the widely available mid-length gas tubes.

Key Facts

• Brand: Daniel Defense
• Model: 18″ 5.56mm, Mid-length, 1:7, S2W
• Manufacturer Part Number: 07-116-05191-018
• Caliber: 5.56mm NATO
• Barrel Length: 18″
• Twist Rate: 1:7
• Barrel Profile: S2W (Daniel Defense proprietary Heavy Barrel)
• Gas System: Mid-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: 2.65 lbs
• Barrel Configuration: Stripped (no gas block fitted)

Who an 18-inch S2W barrel suits

This is a barrel for shooters who fire a lot of rounds in one session and care about where they land. The heavy contour resists heat-driven group dispersion, and 18 inches of barrel gives 5.56 meaningfully more velocity than a 16-inch tube, which extends useful range with heavy match bullets. Designated marksman builds, service rifle competition and long-string training are its natural homes.

Mid-length gas at 18 inches, and the paperwork

Mid-length gas on an 18″ barrel gives a shorter gas system than the rifle-length version of the same profile, so the impulse is a little firmer and the gas block sits closer to the receiver. The benefit is parts availability and a wider choice of handguard lengths that clear the block. Order a mid-length gas tube, not a rifle-length one.

Choose a long handguard from our rails and handguards, pick an adjustable block from our gas blocks and gas tubes, or compare the other heavy options in our Daniel Defense barrels.

Ordering from Western Sport in Roanoke, TX

Since 2007 Western Sport has been a licensed FFL and SOT in Roanoke, Texas, and as a Daniel Defense master dealer with a gunsmith on site we install and headspace heavy barrels regularly. Call 817-393-4000 if you want the upper assembled properly rather than shipped as parts.

Frequently Asked Questions

Q: What does S2W mean?

A: S2W is Daniel Defense’s Strength to Weight profile, which the company describes as its proprietary Heavy Barrel. It carries more steel than the Government or Lightweight contours, which gives greater thermal capacity and stiffness. At 18 inches in mid-length gas configuration Daniel Defense lists this barrel at 2.65 lbs.

Q: Should I choose mid-length or rifle-length gas at 18 inches?

A: Rifle-length gives the lowest port pressure and longest dwell, so the softest cycling, and Daniel Defense builds the S2W profile that way too. Mid-length puts the block closer to the receiver, uses more widely available gas tubes, and allows a wider choice of handguard lengths.

Q: What gas tube length does this barrel need?

A: A mid-length gas tube. This is the mid-length gas configuration of the 18″ S2W barrel, so neither a carbine nor a rifle-length tube will work. Because this SKU is the stripped configuration you also need a .750-inch gas block, and an adjustable one is worth considering on a heavy barrel built for volume fire.

Q: Is 2.65 lbs the weight without a gas block?

A: Yes. Daniel Defense lists 2.65 lbs for this barrel, and since this SKU is the stripped configuration the figure is the barrel alone. Add your own gas block, mid-length gas tube, barrel nut, handguard and muzzle device to estimate the total upper receiver weight; it will be a heavy build.

Q: Does 18 inches give useful extra velocity over 16?

A: Yes, though the gain is incremental rather than dramatic in 5.56. The extra two inches of barrel produce more muzzle velocity, which extends the range at which heavy match bullets stay supersonic and on target. Combined with the stiffness of the S2W contour, that is why this length suits marksman-type builds.

Q: Do I need an FFL for this barrel?

A: No. A barrel is a component and not a firearm under federal law, so no transfer, Form 4473 or background check is required and it ships directly to you. Component regulations differ between states and municipalities, so verify your own rules before ordering if you are outside Texas.

Additional information