thanx, I'll give it a go at 100psi

wow, I cant believe how many replies there are. anyway this is everything I know about the pipes I used.
-bought from bunnings, (sydney) [pvc-pressure pipe fitting 13558 25mm class 12 pipex $6.25] this is what the reciept says. maybe someone knows what pipe it is and the max pressure rating.

my first pneumatic, its more of a rifle than a cannon. cost me around AUS$60 to make. works well at 50psi, but i dont know what type of pvc im using, it doesnt have any printing on the pipes so I wonder how much pressure it could take. It uses a 12bar small, cheap sprinkler valve, air gun trigger ...