Being that it is winter season, I'm a little reticent to game my Mp5 as it's shooting over 400 FPS. I mostly hear of V2s cracking in M4s and on M4's the problem is exacerbated by the open area in front of the gearbox where the hop-up chamber is. This can be mitigated by things like the STS v2 shock transfer system (
http://www.v2fix.com/).
There is no such thing for the Mp5 though, should I be worried about mechbox cracking in cold temperatures?