CMC AR-15 Gas Tubes – Premium Stainless Steel for Every Gas System
Choosing the correct gas tube is essential for consistent cycling, reliable gas delivery, and long-term AR-15 performance. At Ally Munitions, we stock CMC Gas Tubes—precision-engineered components that match or exceed military specifications for fit, finish, and function across all AR gas system lengths.
Whether you're assembling a new build or replacing a worn component, CMC gas tubes offer dependable performance backed by the same quality CMC is known for in their triggers and BCGs.
Key Features
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Material: Precision-machined, corrosion-resistant stainless steel
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Gas System Compatibility: Available for pistol, carbine, mid-length, and rifle-length gas systems
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Installation Hardware Included: Each gas tube ships with its matching gas tube roll pin
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Mil-Spec Dimensions: Built to tight tolerances for optimal gas efficiency and proper cycling
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Made in the USA
Why We Recommend It
These gas tubes are our go-to for both custom builds and field rifles. CMC's attention to detail ensures proper fitment and reliable gas delivery in all conditions. When paired with CMC bolt carrier groups, gas efficiency improves due to better component-to-component compatibility.
Pro Build Tips
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Always install with a 3/32" roll pin punch for proper pin alignment
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A light film of grease on the end of the gas tube that inserts into the gas block generally aids in easier installation, as well as the roll pin itself
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Always test fitment with your roll pin punch before inserting the roll pin—this ensures correct alignment and prevents binding during install
Maintenance Tips
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Inspect your gas block and gas tube annually for carbon fouling or corrosion
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Use pipe cleaners or small bore brushes to clean the gas tube interior
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If you don’t want to clean it—simply replace it. Gas tubes are inexpensive and easy to swap
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Always use a new roll pin when reinstalling a gas tube—once removed, old pins are no longer reliable
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Check that the gas tube is free of dents, fouling, or corrosion that might restrict flow
Know Your System – Gas Length Guide
If you’re unsure which gas tube you need, measure from the center of the gas port on your barrel back to the upper receiver (chamber area). This measurement will help identify the gas system length:
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Pistol: ~4″
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Carbine: ~7″
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Mid-Length: ~9″
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Rifle: ~12″
We are currently building a master reference guide covering gas system lengths, tube dimensions, and recommended barrel pairings. Stay tuned!
