Have you upgraded your missiles? I upgraded to ice missiles and now they do more damage. the max damage you should be able to do pre-hardmode is 120, and that's with a fully charged ice wave spazer beam.Spazer isn't that rare, and is also craftable, I believe. A few pages back I detailed a small test I conducted and it's super overpowered. It's made my beam completely outclass my missiles. My hope is that it gets nerfed at some point soon.