[Nomadic Mentor]

If you have the resources go metal not only does it look cooler it's also safer. If you can put it on a turret that's bonus points. There are a bunch of threads talking about the different approaches for tee shirt launchers I would do a search for them and read up on some of the discussions if you haven't already and go from there if you have specific questions left just ask. And yes it seems like you could make these part work for a cannon the only thing left missing is a good solenoid. Be safe and do the research; it makes it a lot more fun when your launching stuff with your cannon.