CMMG Rifle Length Gas Tube with Roll Pin

The CMMG Rifle Length Gas Tube with Roll Pin (Part No. 55DA196) is a direct-impingement system component designed for AR-platform rifles requiring reliable gas management across sustained fire. This gas tube assembly channels propellant gases from the barrel to cycle the bolt carrier group, making it a critical element in the rifle's operating cycle. The rifle-length configuration is optimized for longer sight-radius setups and mid-length to rifle-length receivers where gas port dwell time demands proper tube diameter and length matching.

The included roll pin serves as the primary retention mechanism, securing the gas tube to the gas key on the bolt carrier group. Proper installation and fit of both tube and pin are essential for consistent bolt carrier cycling and extraction reliability. Gas tubes wear over time as the pin and tube interface absorb thousands of firing cycles; replacement becomes necessary when wear causes gas leakage or carrier tilt. This CMMG-manufactured component meets mil-spec tolerances for drop-in compatibility with standard AR receiver groups and gas blocks designed for rifle-length systems.

Operators conducting high-round-count training, competitive shooting, or duty-rifle maintenance will find replacement gas tubes essential for keeping rifles in service. Field maintenance, suppressed fire adjustments, and extended range sessions create wear that eventually forces gas tube rotation. This CMMG assembly provides a straightforward, verified replacement for worn components, restoring proper gas system function without requiring specialized fitting or modification to the host rifle.

Rifle-length gas systems remain standard on full-size AR-pattern rifles and many precision rifles where barrel length exceeds 16 inches. Understanding your current gas tube length—rifle, mid-length, carbine, or pistol—is critical before ordering, as mismatched lengths result in cycling problems or failure to function. TacticalSurplusUSA stocks genuine CMMG replacement components to keep your platform running when duty demands it.