expansion chamber/ gas thru foregrip

[paintball24]

whats is the difference between a expansion chamber and a gas thru foregrip? i have a piranha but dont know which i have, help.

[Crash Danger]

Gas through simply allows the gas to pass through your bottm line but with a grip to hold on and an expansion chamber allows for the CO2 to expand and work better in cold weather.

Gas thru grips don't really give an increase in performance of your gun, but expansion chambers do