Posted - Mar 12 2011 : 10:44:51 AM Punkin' Chunkin' is a huge event. They even cover it on Daily Planet every year. Some of the stuff they make is just astronomical. I wonder though if they have done tests at various pressures? Mythbusters didn't see any different between say, 10PSI and 50PSI. I've never built an air cannon so I have not played with it much.