Lancer Tactical Airsoft Flat Surface Cylinder for Short-Size Inner Barrels

Most players never think about their inner barrel cylinder until it's already a problem — a gun that's losing power, leaking gas, or stripping pistons after a spring upgrade. This is the Lancer Tactical flat surface cylinder for short-size inner barrels, and it's the part you swap in to fix air seal issues in a V2 gearbox running a short barrel.

Why a flat surface matters. Standard cylinders have a curved outer surface. Shimming them — setting the vertical clearance between gears inside the gearbox shell — is fiddly because you're fitting a curved piece into a flat space. A flat surface cylinder removes that variable: the cylinder sits evenly, shims go in cleanly, and you can set the angle of engagement without the cylinder crowding the shim stack. That is genuinely useful work when you're building a gearbox to handle a heavier spring or cleaning up after a stripped piston.

Short-barrel matching. Short-size inner barrels have less volume than standard-length tubes, so the cylinder needs to release air at the right moment rather than over-compressing on the piston. This cylinder is sized for that application. Pairing it with a short barrel means you're not wasting gas on air that the barrel can't use.

CNC aluminum. The cylinder is machined from aluminum, not injection-molded plastic. That means it won't crack under heavy spring loads, and the flat surface stays true. It weighs 1.4 oz, which is a fraction of the total gearbox weight and makes no practical difference on the gun.

Before you buy. Make sure your barrel is short-size, not standard-length. This is an internals swap — you need to split the gearbox to replace the cylinder, and it's the right time to check your AOE, air seal, and shim stack at the same time. If you haven't opened a gearbox before, plan on watching a few teardown videos first.

Includes the cylinder only.