Had hundreds of problems. So many that I dismantled the entire thing and gave up. After some inspiration from [kmancreeper412] and my mom, I took the parts I had and started over.
Also the propellant cannon fired a few homemade foam rubber darts, but we decided to put that to the side for now because firing was inconsistent, hairspray is nasty, safety risks, and just not as much fun as we first thought. We would much rather have a separate project dedicated to an air pressure cannon.