Prometheus EG Stainless Steel Inner Barrel 370mm 6.03mm for Tokyo Marui M4A1 MWS

Specifications

• Brand: Prometheus
• Series: EG Barrel
• Model Fit: Tokyo Marui Gas Blowback M4A1 MWS
• Length: 370 mm
• Inner Diameter: 6.03 mm ±0.01 mm
• Outer Diameter: 8.5 mm
• Material: Stainless Steel (SUS)
• Made In: Japan
• Compatibility: Tokyo Marui spec inner barrels and common compatible outer barrels

Features

• Ultra-tight 6.03 mm bore with +/-0.01 mm tolerance for exceptional shot-to-shot consistency
• Stainless steel construction (SUS) offers dimensional stability and long service life without coating wear
• 370 mm length optimized for Tokyo Marui M4A1 MWS platforms for balanced range and handling
• 8.5 mm outer diameter ensures reliable seating in most outer barrels
• Part of the Prometheus EG lineup — multiple lengths available to fine-tune range/handling
• Manufactured in Japan under strict quality control for repeatable performance

Precision Tightbore for Serious Accuracy

The Prometheus EG stainless steel inner barrel is a no-compromise tightbore upgrade made for players chasing tighter groups and rock-solid consistency. At 6.03 mm (±0.01 mm tolerance) this barrel stabilizes BB flight, reduces air loss, and helps you string repeatable shots — exactly what you want when dialing your MWS for accurate, predictable performance.

Made for Tokyo Marui M4A1 MWS Builds

With a 370 mm length tuned specifically for the MWS platform and an 8.5 mm outer diameter for secure seating in common outer barrels, this EG barrel drops into Marui-spec setups cleanly. Constructed from SUS stainless steel, it keeps its dimensions over time without relying on soft coatings that can wear off — a durable choice for both daily use and high-performance builds.

Japanese Quality and Practical Fitment

Part of the respected Prometheus EG series, this barrel is manufactured in Japan under tight QC standards so you get consistent tolerances and long-term reliability. It’s ideal for players upgrading a stock MWS or building a precision GBB project where consistency and material stability matter most. Verify local joule/energy limits before installation and test across conditions to ensure compliance.