Lancer Tactical M90 Piano Wire Steel Spring, 280 - 340 FPS

Every AEG starts with the spring the factory dropped in. The M90 from Lancer Tactical is the go-to replacement when you need a spring that sits comfortably inside most field limits, especially indoors.

What the M-rating means. M90 is a rough guide to velocity in an otherwise standard setup. The spring is rated 280–340 FPS on 0.20g BBs, which puts you inside typical indoor caps and well below outdoor limits. The actual number you see on a chrono depends on your gearbox shimming, air seal, cylinder volume, and barrel length, so treat the rating as a starting point, not a guarantee. Chrono with your own BBs before game day.

Material and fit. Made from piano wire steel, which is the standard spring material across the hobby: it holds tension well and resists metal fatigue through normal use. Fits most AEG gearboxes, including Version 2 and Version 3 platforms. On a V2, swapping the spring means splitting the gearbox shell, so budget time and patience. A V3 with a quick-change guide lets you pull the old spring and drop this one in through the back without opening the box.

What it's for and what it isn't. An M90 is a light spring. It's the right choice for indoor play, low-impact fields with strict caps, or a gearbox you want to run easy on. It's not the spring you reach for if you're chasing outdoor DMR range or running a heavy spring setup. Fitting an M90 into a gearbox built around M120 gears and a torque motor is mismatched, and the gears will be overkill for what the spring can pull.