Maple Leaf 100mm 6.02mm Brass Inner Barrel for G17/18 & Hi-Capa 4.3 GBB Pistols, Silver

GBB pistols live or die by their hop-up and barrel. The stock plastic chamber and generic brass barrel that come in most pistols are good enough for backyard skirmishes, but they fall apart at 50 feet. The Maple Leaf 6.02mm inner barrel is the upgrade that fixes that.

Precision bore. Maple Leaf machines these to 6.02mm instead of the generic 6.03–6.04mm you get in factory barrels. That tighter fit reduces the gap between the BB and the barrel wall, which means more consistent air seal and less wobble as the BB travels. The result is tighter groupings, especially when you pair it with heavier BBs like 0.25g or 0.28g.

Length and material. At 100mm, this is a standard short-barrel dimension for GBB pistols. It preserves the slide-to-muzzle balance while giving you a marginal velocity bump over the stock barrel. The barrel is brass with nickel plating, which resists corrosion better than bare brass and holds up to the heat of rapid firing.

What it fits. This barrel works with G17/18, Desert Warrior, Hi Capa 4.3, and P226 platforms. If you are running a clone GBB, check your inner barrel length before ordering—some variants run slightly shorter or longer.

Installation. Swapping an inner barrel on a GBB pistol is straightforward but requires removing the slide and barrel assembly. You do not need special tools beyond a small punch or allen key, but if you have never taken your pistol apart, watch a guide for your specific platform first. Once installed, the barrel is permanent until you choose to swap it again.

What this is not. This is a pistol barrel, not a rifle upgrade. It will not turn your GBB into a field-grade carbine, and it does not include a hop-up bucking or chamber. You get the barrel only.