Spring Upgrades

[porthose]

I have an m4-a1 and i play airsoft quite often, the people i play with like to play stock guns and no spring upgrades. But i would like to purchase a spring to put in my gun for events like wolverine fury and others to come. See the thing is my gun shoots just fine with the guys i play with, but for events like wolverine fury i dont want to be out gunned or out reached by a lot. So i was wondering, what % spring should i but if i want to be shooting about 350-390.

Any help would be appreciated. Oh and cost for these items are helpful too.

[Jacko]

I think a PDI 150% spring should get you to 350 FPS pretty nicely. You'll need some metal bushings too, but all of that should cost less than $50 shipped.

[sUpEr K-@Z2-K]

M120 should working nicely... however metal bushings might not be enough to ensure the safety of your gearbox

consult with WTS you might need reinforced gears

[porthose]

I'm about as sharp as a baseball. That's why I used stupid text speak. guys for your help im think i might just order a 130% and get up to about 320 fps, that shoud be good enough.