piston weight

[tape fist]

Im just putting some final touches to my air cannon and i wanted to ask how heavy should a piston be?The reason i ask is because im using a socket and even though it slides freely in an out when using my breath i didnt want to take the chance of screwing up.

Some detail:It is the same diameter as the inside of a 1 in. pipe and is about 1 in. in length.

[ALIHISGREAT]

As light as possible... but you also need to do things like minimise pilot volume and the piston needs to seal well with the housing too.