CMC Triggers AR 15 AR 10 Pistol Length Gas Tube Black Nitride 304 Stainless Steel 81621 UPC 859464006307
Product Description
The CMC Triggers® AR-15 / AR-10 Pistol-Length Gas Tube (SKU: 81621 / UPC: 859464006307) is an essential, high-reliability direct-impingement component engineered to handle the brutal pressures and thermal cycles typical of short-barrel carbines, PDWs, and AR pistols. Designed for seamless integration into Mil-Spec receiver assemblies, this pistol-length tube ensures unrestricted, laminar gas delivery from the gas block directly into the carrier key to guarantee consistent cycling across defensive, tactical, and duty mission profiles.
Precision-drawn from high-grade 304 austenitic stainless steel, this gas tube delivers exceptional structural rigidity and resistance to heat-induced warping. CMC Triggers elevates this component by applying an advanced Black Nitride (ferritic nitrocarburizing) surface treatment. This thermochemical process alters the steel's surface matrix to yield extreme resistance against hot propellant gas cutting, friction, carbon fouling, and environmental corrosion, eliminating the reflective glare of untreated raw stainless steel behind your handguard.
Engineered to precise Mil-Spec 0.180-inch outer diameter tolerances, the 81621 gas tube slips effortlessly through standard barrel nut channels and receiver cloverleaf bores without binding or friction against the bolt carrier group's gas key. Shipped complete with a corrosion-resistant retaining roll pin, this gas tube provides a rugged, mission-ready upgrade or replacement for suppress-tuned 300 Blackout setups and ultra-compact tactical platforms.
*Armorer Bench Notes & Real-World Staging Guidance:*
Fitment Matrix: Direct-impingement AR-15 and AR-10/SR-25 pattern barrels featuring a standard pistol-length gas system (6.705" nominal overall length). CRITICAL: Gas tube must be installed with the downward discharge gas port oriented directly over the barrel port within the gas block. Ensure proper gas block alignment before pinning or torquing set screws. Do NOT use this tube on carbine, mid-length, or rifle-length gas systems. Verify that the gas key engages the tube flare smoothly without binding when the bolt carrier group moves into battery.
- Ensure the host firearm is completely clear, magazine removed, and chamber visually and physically verified empty.
- Slide the forward end of the gas tube into the rear bore of your gas block, ensuring the tube bend curves upward toward the handguard interior and the bleed hole faces downward into the gas block barrel journal.
- Align the roll pin cross-hole in the gas block with the pre-drilled pin hole in the gas tube; support the gas block on a bench block and drive the included 5/64" roll pin using a dedicated roll pin punch until centered flush on both sides.
- Slide the gas block and tube assembly over the barrel journal while feeding the rear end of the gas tube through the barrel nut and upper receiver gas tube port.
- Perform a bench function test by slowly guiding a stripped bolt carrier into battery to ensure the carrier gas key mates cleanly over the flared tube tip without off-axis friction or resistance.
Key Features
- Precision 304 Stainless Steel Construction: Resists thermal deformation and withstands severe gas port erosion under sustained fire.
- Advanced Black Nitride Finish: Provides superior surface hardness, reduced carbon adhesion, enhanced corrosion protection, and a low-glare tactical aesthetic.
- Optimized Pressure Transfer: Engineered 6.705-inch length delivers consistent backpressure dynamics essential for short-barrel direct-impingement reliability.
- Universal Mil-Spec Fitment: Compatible with all standard AR-15 and AR-10 pistol-length direct-impingement barrels and standard-profile gas blocks.
- Installation Hardware Included: Ships complete with a heavy-duty stainless steel gas tube roll pin for immediate armorer installation.
- Proudly Made in the USA: Manufactured to exacting tolerances and backed by CMC Triggers' 100% Lifetime Warranty.
Product Specifications
- Brand: CMC Triggers®
- Model/Series: AR-15 / AR-10 Gas Tube
- MPN / SKU: 81621
- UPC: 859464006307
- Gas System Length: Pistol-Length (6.705" Overall Length)
- Material: 304 Stainless Steel
- Surface Finish: Matte Black Nitride (Salt Bath Ferritic Nitrocarburizing)
- Outside Diameter: 0.180 Inches (Mil-Spec Standard)
- Platform Compatibility: Direct-Impingement AR-15 & AR-10 / SR-25 Barrels
- Included Accessories: Stainless Steel Gas Tube Roll Pin
- Country of Origin: United States
