Description
The gas tube is one of those small parts that does a big job, quietly routing gas from the barrel back to the bolt carrier every time you pull the trigger. WMD Guns builds this one to a rifle length, which is the setup you want when you're running a 20-inch or longer barrel on your AR-15. It's cut from 304 stainless steel and measures right around 15 3/16 inches, putting it squarely in the range a true rifle-length gas system calls for.
What the Nitromet Finish on This Gas Tube Actually Does
Nitromet is WMD's salt bath nitrocarburizing process, and it's the reason this tube stands apart from a plain stainless part. The treatment drives hardness up to around Rc 55 on the surface, which translates to better resistance against the heat and fouling that a gas tube lives with shot after shot. That harder, slicker surface also fights corrosion, so you get a longer service life out of a component that takes a beating every range trip. The matte black color is a nice bonus if you're going for a clean, uniform look under the handguard.
Fitting the WMD Rifle-Length Gas Tube to Your Build
This is a Mil-Spec part, so it drops into standard AR-15 gas blocks and front sight bases without drama. Rifle-length systems place the gas port about 12 inches from the chamber, which gives you a smoother, softer impulse and a bit less wear on the rest of your rifle compared to shorter setups. If you're assembling a classic 20-inch rifle or a longer precision build, this is the tube length that matches. Installation is straightforward with the right roll pin punch and a steady hand.
WMD Guns has a solid reputation built on coating and finishing know-how, and that experience shows in a part this simple. It's the kind of upgrade that you install once and forget about, which is exactly what you want from a gas tube.
Key Specifications
- Manufacturer: WMD Guns
- Manufacturer Part Number: 1-NMGTR
- UPC: 855899003201
- Gas System Length: Rifle-Length
- Length: 15 3/16 in
- Material: 304 Stainless Steel
- Finish: Nitromet (Salt Bath Nitrocarburized)
- Surface Hardness: Approx. Rc 55
- Color: Matte Black
- Fitment: Mil-Spec AR-15
- Product Type: Part
What’s Included
- WMD Guns rifle-length Nitromet gas tube
- Gas tube roll pin
Frequently Asked Questions
What barrel length does this rifle-length gas tube work with?
A rifle-length gas system is built for barrels 20 inches and longer, where the gas port sits about 12 inches out from the chamber. That longer distance gives you a softer, smoother recoil impulse and less wear on your bolt carrier group. If you're running a shorter barrel, you'd want a carbine or mid-length tube instead.
What is the Nitromet finish on this WMD gas tube?
Nitromet is WMD Guns' salt bath nitrocarburizing process applied to the stainless steel. It raises the surface hardness to around Rc 55 and boosts resistance to heat and corrosion, which are the two things that wear a gas tube down over time. The result is a tougher, longer-lasting part with a clean matte black look.
Does the WMD rifle-length gas tube come with a roll pin?
Yes, it ships with the gas tube roll pin needed to secure it to your gas block or front sight base. You'll want a proper roll pin punch and a steady hand for the install. Everything else you need beyond that is standard AR-15 gear.
Will this gas tube fit a standard AR-15 gas block?
It's a Mil-Spec part, so it fits standard AR-15 gas blocks and front sight bases without any modification. As long as your build is set up for a rifle-length gas system, this tube drops right in.




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