Hi good folks, does anyone know the weight of a full 6.35kg bottle of gas the reason i ask is, when i got mine back iv April it was sowing 50bar it is now showing a tad over 20 bar, i am being told by my supplier i can change it £15-00 but they can't let me have another even if i take a new contract out, i have no way of knowing how much is left in it other than 20 bar and i don't want to run out to find i can't one