Actually cutting springs put's serious strain on gearbox parts. Either replace the spring with an M110 and invest in a tightbore barrel or sand down the sides of the spring. Thats right, get out a peice of sand paper and sand down the sides (long ways, like you were polishing the outside of a gun barrel) this reduces the strength of the spring (although not catastrophically) and doesnt strain your gearbox parts with sharp pointy edges. Sand it down a couple of times, chrono, repeat untill you get in your desired FPS range... M110 is probably a better idea though.
