Description
The CMMG Gas Tube Kit is a stainless steel replacement gas tube for AR-15 platform rifles. Each kit includes the gas tube and a 5/64″ x 5/16″ roll pin for securing it to the gas block.
The gas tube connects the gas block on your barrel to the gas key on your bolt carrier group. When a round fires, gas travels through the barrel’s gas port, into the gas block, through the tube, and back into the upper receiver to cycle the bolt. It’s a straightforward part, but it needs to be the correct length for your barrel’s gas system — an incorrect length tube will not function.
Available in four lengths:
- Pistol — for pistol-length gas systems (typically barrels under 10″)
- Carbine — for carbine-length gas systems (typically 10″–14.5″ barrels)
- Mid-Length — for mid-length gas systems (typically 14.5″–18″ barrels)
- Rifle — for rifle-length gas systems (typically 18″+ barrels)
These are general guidelines. Always confirm your barrel’s gas system length with the barrel manufacturer’s specifications before ordering, as some barrel makers use non-standard gas port locations.
Installation requires a roll pin punch and hammer. The tube inserts through the upper receiver and into the gas block, then is secured with the included roll pin driven through the gas block’s pin hole.
Specs:
- Material: Stainless steel
- Included: Gas tube + 5/64″ x 5/16″ roll pin
- Compatibility: AR-15 platform
- Available lengths: Pistol, Carbine, Mid-Length, Rifle
