CMMG Mid-Length Stainless Steel Gas Tube Kit with Roll Pin - 55DA1EE

CMMG Gas Tube Kit with Pin - Mid-Length - 55DA1EE - 815835012391

Product Description

Maintaining proper gas regulation, dwell time, and cycling reliability in a custom mid-length AR-15 barrel assembly requires a high-precision, heat-resistant gas tube. Worn, bent, or corroded gas tubes cause severe gas leakage around the gas block journal, resulting in failure-to-extract, short-stroking, or erratic bolt carrier travel. The CMMG Mid-Length Stainless Steel Gas Tube Kit (55DA1EE) addresses cycling inconsistency and gas erosion by providing a heavy-duty, Mil-Spec dimensioned direct-impingement gas tube engineered for intense thermal cycles.

Precision-drawn from high-grade stainless steel, the 55DA1EE features a nominal length of 11.75 inches designed specifically to mate with mid-length barrel gas ports. The raw stainless steel finish offers inherent resistance against extreme internal gas temperatures, carbon fouling, and environmental corrosion without chipping or flaking over high round counts. Both the gas block roll pin interface and gas key mushroom tip are machined to strict Mil-Spec tolerances, guaranteeing smooth entry into the upper receiver gas tube keyway without binding against the bolt carrier key.

Ideal for custom upper receiver builds, gas system overhauls, or barrel replacements on 14.5-inch and 16-inch mid-length AR-15 carbines, the CMMG 55DA1EE comes complete with a steel gas tube roll pin for straightforward, secure armorer installation.

*Armorer Bench Notes & Real-World Staging Guidance:

Fitment & Platform Compatibility Matrix: Fits standard Mid-Length AR-15 and AR-10 / LR-308 Barrel Assemblies utilizing a mid-length gas port position (~11.75" tube length). Compatible with standard 0.625", 0.750", and 0.875" gas blocks (low-profile or A2 front sight towers).

Installation Sequence:

1. Safety check the firearm: clear magazine, lock bolt rearward, and physically/visually inspect chamber to verify clear weapon.
2. Slide the rounded end of the CMMG 55DA1EE gas tube through the front of the upper receiver gas tube port to verify alignment with the barrel nut.
3. Insert the gas tube into your gas block, ensuring the gas port hole facing downward aligns with the internal port of the gas block.
4. Secure the gas tube to the gas block using the included roll pin and a dedicated gas tube roll pin punch set.
5. Slide the gas block and tube assembly onto the barrel journal, seat the rear end into the upper receiver keyway, and verify that the bolt carrier gas key slides over the gas tube tip without binding.

Key Features

• Mil-Spec Mid-Length Geometry: Engineered to exact 11.75-inch specs for seamless alignment with mid-length gas system barrels.
• Premium Stainless Steel Construction: High thermal threshold resists gas erosion, deformation, and high-volume firing stress.
• Natural Stainless Finish: Surface resists carbon buildup and provides excellent long-term corrosion protection.
• Precision Gas Key Mushroom Tip: Formed to match bolt carrier gas key entry, ensuring efficient gas seal without binding.
• Roll Pin Included: Ships with a heavy-duty steel gas tube roll pin for immediate assembly.

Product Specifications

• Brand: CMMG
• Model: Mid-Length Gas Tube Kit with Pin
• MPN: 55DA1EE
• UPC: 815835012391
• Platform Compatibility: AR-15 / AR-10 Mid-Length Gas Systems
• Gas System Length: Mid-Length (~11.75 inches)
• Material: Stainless Steel
• Finish / Color: Natural Stainless
• Included Components: Gas Tube, Gas Tube Roll Pin