Atlas Custom Works AAP-01 Aluminum Outer Barrel Type C, Green

What this barrel changes. The Atlas Custom Works Type C outer barrel replaces the stock tube on your Action Army AAP-01 GBB pistol. It's machined from aluminum, which keeps weight down at 60 grams while giving you a more substantial feel than the factory polymer option. The green finish is a straightforward color choice for matching or contrasting with your slide and frame.

Why swap an outer barrel. This is primarily an aesthetic and tactile upgrade. You're not changing internal performance—the inner barrel and hop-up stay the same, so velocity and grouping don't shift. What you get is a different profile, a different color, and the ability to coordinate your pistol's look with the rest of your loadout. Aluminum also resists wear better than polymer if you're running it in a holster or against hard surfaces.

Fit and installation. This barrel is made specifically for the Action Army AAP-01 GBB platform. It won't fit other pistols, even ones that look similar. Installation typically requires basic hand tools to remove the slide assembly and swap the outer barrel. If you're not comfortable disassembling your GBB, let a tech handle it the first time. Once installed, it stays put through normal use.

What's in the box. Just the outer barrel. No mounting hardware or tools are included, and the AAP-01 pistol itself is not part of this purchase.