Maple Leaf 6.02mm 106mm Nickel-Plated Brass Inner Barrel for G17/18, Desert Warrior, Hi-Capa 4.3, P226, Silver

Why an inner barrel matters on a GBB pistol. The factory barrel in most GBB pistols is a mass-produced part with a 6.03mm bore and inconsistent machining. That's fine for casual skirmishing, but once you start paying attention to your groupings, the barrel becomes the first thing to upgrade. A precision inner barrel tightens the fit between the BB and the bore, which stabilises the projectile and makes the hop-up more predictable. You get tighter shot-to-shot groupings without touching the hop-up itself.

The 6.02mm bore. This is a precision bore size, slightly tighter than the standard 6.03mm you find in factory barrels. The tighter fit reduces wobble and gives the hop-up a more consistent contact patch, which translates to flatter trajectories and better accuracy at distance. The trade-off is that you need good-quality BBs — 0.25g or heavier — and any burrs or debris in the barrel will cause feeding issues. Break it in with a few hundred rounds of premium BBs before you judge the performance.

Brass with nickel plating. Maple Leaf builds these from brass, which machines to a tighter tolerance than the stamped steel in budget barrels. The nickel plating adds corrosion resistance and keeps the bore smooth as it breaks in. Brass also conducts heat slightly better than steel, which helps maintain consistency during rapid strings of fire.

106mm length and what it means. At 106mm, this is a mid-length barrel for GBB pistols. It gives you a modest boost in velocity and accuracy over a stubby 80mm barrel, without the bulk of a 130mm or longer option. Most GBB pistol frames clear the muzzle without printing, but you should check your slide-to-barrel clearance before you buy, especially if you're running a threaded adapter or compensator.

Compatibility. This barrel fits G17/18, Desert Warrior, Hi Capa 4.3, and P226 platforms. These are all standard GBB pistol frames with similar barrel housing dimensions. It does not fit GBB rifles or AEGs — this is a pistol-specific part.

What you'll need. Installation requires a barrel removal tool or a punch to drive out the barrel guide pin. If you've never done this before, budget time for a first-timer install or have a tech do it. You'll also want to break it in with premium BBs and expect a few hundred rounds before the barrel settles into its final accuracy.

Includes only the inner barrel. No installation tools or BBs are included.