Hello, I am a high school senior making a railgun for my science fair project. I have been searching the internet and have finally come up with a plan for my railgun. I have some questions about my plan before I go out and buy materials. I have two questions currently, one about rails and one about projectiles. I have attached an image to show my plan for the rails and for the two projectiles. Rails: I plan on using 1/2" copper pipe (8-10" long) for my rails. I will surround and seperate the copper pipe with PVC pipe. Will a circular bore work instead of a rectangular one? All the railguns I've seen are rectangular and I wanted to know if it would be possible to make one circular. I also understand that 1/2" copper pipe is very big for a railgun(at least one that would be fairly inexspensive). I want to fire the projectile at roughly 100m/s. Approximately how much force would that take? Projectiles: My first projectile question is whether or not the round has to be magnetic. If it doesn't I was planning on using normal aluminum bought from a local hardware store. The dimensions I plan on using are in the attached image. The second projectile is more of an experimental round. I plan on buying several pistol cleaning brushes (for those who don't know what that looks like, I have a picture in the attached image). They will have a stainless steel body along with stainless steel bristles. I got the idea from RP181's nylon round with the wires inside. I hope the cleaning brush projectile will add a sabot like affect as well as reduce the mass of the projectile. Thank you for viewing the thread. I will be posting many more questions in the near future. All comments are greatly appreciated. Hopefully my questions make some sense, I'm sorry for my limited knowledge of electromagnetism and railguns, but I hope to gain some as I continue my science fair project.