Maple Leaf G/EU Series Chamber Set with 6.02mm Inner Barrel & 60° Autobot

Upgrading the chamber on a GBB pistol is the single change that gives you the biggest jump in consistency — it's where hop is applied to the BB, and any flex, play, or misalignment in the stock chamber translates directly into inconsistent shot placement. The Maple Leaf chamber set replaces three components in one go: chamber, inner barrel, and bucking, with everything pre-aligned and ready to drop in.

The 6.02mm bore is a true precision tightbore. Compared to OEM 6.04mm or 6.08mm bores, the tighter 6.02mm holds the BB more positively as it travels down the barrel, reducing the air loss around the BB that causes shot-to-shot velocity variance. The trade-off is that 6.02mm is more demanding of BB quality — cheap or out-of-spec BBs will jam more readily than in a looser bore. Match this with quality BBs (0.25g or heavier) and you'll see noticeably tighter groups at 30m+.

The 60° Autobot bucking is Maple Leaf's established design for GBB pistols. The 60° hardness rating is the all-rounder choice — firm enough to apply consistent hop on heavier BBs, soft enough to seal effectively against the BB on lighter weights. Autobot is the gear-pattern ridge bucking, which generates hop through mechanical engagement with the BB rather than pure compression. The result is more consistent hop application across the magazine, particularly on cold mornings when bucking compression on simpler designs becomes inconsistent.

Compatible with the broad G/EU pistol family: Tokyo Marui, WE, Army Armament, Vorsk, AW, and most other manufacturers using the standard Glock/EU chamber form factor. Three length options cover sub-compact through long-slide builds: 84mm for compact Glock 19-class and shorter, 97mm for standard Glock 17-class, and 113mm for long-slide builds and competition pistols. Check your barrel length before ordering — the chamber must match the slide's internal barrel travel.

Specifications