Lancer Tactical CNC Steel Slotted Surface Cylinder for 300-400mm Inner Barrels, Chrome

Changing an inner barrel without changing the cylinder is the most common AEG upgrade mistake. The cylinder's air volume needs to roughly match the barrel's, and a slotted cylinder is how you make that happen for shorter builds.

What the slot does. The port slot in the cylinder wall releases air earlier in the compression cycle, so the air column pushing the BB doesn't have to fill a chamber sized for a longer barrel. Pair a full cylinder with a 300mm barrel and you're wasting compression as noise and piston stress. Match them, and the shot is crisper and the grouping tightens. This one is cut for the 300 to 400mm inner barrel range.

Build. CNC-machined steel with a chrome finish. Tight tolerances on the cylinder bore are what keep air-seal consistent from shot to shot, and the steel construction holds those tolerances under repeated piston impact.

Pair it with a ported piston head — the ports on both parts need to line up for the cylinder to do what it's designed to do.

One part doesn't fix a leaky air seal on its own. You still need the piston head O-ring, cylinder head O-ring, and nozzle all seating properly. But getting the cylinder right for your barrel length is the step most builders skip, and it's the one that makes the difference between a gun that shoots soft and one that actually uses what the spring is giving it.