Atlas Custom Works 6061 Aluminum 125mm Hex Outer Barrel for TM Hi-Capa M11 CW GBBP, Green

The hex barrel is the cleanest way to protect your Hi-Capa's inner barrel while adding a purposeful look. This Atlas Custom Works outer barrel is machined from 6061 aluminum, so it resists dings and wear without the weight penalty of steel. The hex profile isn't just aesthetic—it gives you a rigid, true cylinder that stays straight shot after shot, which matters when you're chasing consistent grouping.

Length and fit. At 125mm, this is the standard full-length outer for TM-spec Hi-Capa GBB pistols. It clears the slide when cycling and mates cleanly with the inner barrel and hop-up assembly. The M11 clockwise threading accepts standard M11 suppressor adapters and mock suppressors, so you can add a silencer or flash hider without hunting for a special adapter.

What changes with an outer barrel swap. An outer barrel protects the inner barrel from debris and impact, and it gives you a platform for mounting accessories. It does not change velocity or accuracy by itself—those come from the inner barrel quality, hop-up tuning, and BB weight. If your goal is longer range, start with the hop-up and inner barrel, not the outer.

Installation. The package includes two O-rings, which seat between the outer and inner barrel to maintain air seal. A proper fit is critical: too loose and you lose velocity, too tight and you risk binding the slide. If you're not comfortable disassembling your GBB, have a tech handle the install—airsoft pistols are spring-loaded and unforgiving of mistakes.

The Green finish is anodized aluminum, not paint, so it won't chip with normal handling. This is a functional upgrade for Hi-Capa owners who want a cleaner profile and the option to run a suppressor adapter, not a drop-in performance fix.