Lancer Tactical Quenching M150 AEG Spring, Black

You want to push your AEG past the stock spring without tearing through gear sets every few weekends. The M150 is the next step up — hot-quenched for better fatigue resistance, meaning it maintains its rate under repeated compression longer than a standard spring of the same rating.

Where M150 lands you. Spring ratings are not guaranteed velocities — they are rough guides that shift with your gearbox, cylinder, barrel length, and air seal. In a typical outdoor setup, an M150 pushes into the 380–420 FPS range on 0.20g BBs, which is the sweet spot for fields capping at 400. Some builds will sit lower; some higher. Chrono yours before your first game.

What else needs to change. A heavier spring puts more stress everywhere: the piston takes harder hits, the gears see higher torque, the motor draws more current, and the battery heats up faster. Pair an M150 with a high-torque motor — not a speed motor — or you will stall it. A MOSFET and a battery that can handle the discharge current are not optional on this rating. If your gearbox still has stock bushings, consider oil-lite replacements before you drop in the new spring.

Installation. Standard Version 2 gearboxes require splitting the shell to swap the spring. This is not a quick-change setup, so you will need a proper tool kit and patience. Lancer's quenching process gives the spring better cycle life, but bad shimming or wrong AOE will still eat gears regardless of how good the spring is. Get the clearance right first.

This is a spring only. Winding arms, spring guides, and piston upgrades are sold separately.