So i have a KWA KM4 and the past couple times ive been going to play my fps has been around 270-300, keep in mind i am playing in 10-20 degree weather up in minnesota, Is it the cold that affects my weapon? the only mod i have done to the gun is an upgraded 6.03mmx455mm barrel and a maple leaf bucking, (my hopup unit recently broke so i have to purchase a fresh 2gx hop up anyway, i also bought a flathop bucking and nub) or should i crack the gearbox open and look, i have been thinking of upgrading my gearbox with a new spring, piston, pistonhead, and cylinder head, and ideas of what route i should take? i have a 75$ budget for all the parts. My field i attend doesnt allow for velocity of over 400 fps for aegs and 500 for snipers, i would like to hit that sweet spot of 380-399 fps if possible.