see the problem with gas guns is that on really hot days, they shoot harder. so at 20C it may shoot 400 fps.. but on a 30C day it will put you over. Hell it can even swing that much from morning to afternoon.
I've seen 5 kwc DEs, not one of them shot under 400.
I futz with V2s, V3s and V6s. I could be wrong... but probably, most likely not, as far as I know.