Hey Fraz:
I didn't express myself well, sorry but my english is not good. I agree with you, it is not a problem, it is the design. I understand the function of the cooper tubes, the air enters thru them allowing the fuel to go out of the gun.
I was trying to explain that the fuel gun does not leak if you use it right. Most of the peaple thinks that the fuel gun is completly sealed, which is not true.Maybe in the future the designers will put a kind of valve on the copper tubes, blocking them when the trigger is not pressed.
regards