I am honestly curious as to how many people know about the alternate fire mode. The one where you hold down the fire trigger to build up a charge and create a bigger explosion. I constantly see people just spamming shots and using up a cannon in two waves, when you can clear a wave with one or two charged shots. You can also throw grenades while holding a cannon. You can also safely drop them to kill dregs and vandals with your normal weapons, as long as you don't die. You can also use your super while holding the cannon, but I believe it drops the cannon.