If the CO2 is in a liquid state it will need some head space to evaporate into to provde gas pressure. If you're over full then the head space will be insufficient for enough evaporation to take place between shots.
If the CO2 is in a liquid state it will need some head space to evaporate into to provde gas pressure. If you're over full then the head space will be insufficient for enough evaporation to take place between shots.