I wonder what would be the technical challenges of a railgun powered rocket/capsule to launch small payloads to space, technically the remaining concern would be the G force from the acceleration.
Basically even if you build a suitably large one, you might get as few as 1 shots from the structure before having to replace the entire rail.
For an actual weapon, this is potentially worth it at a pretty low number since the weapon itself will be pretty small. For a rocket accelerator sled this is going to be more of a problem (but like, conversely you could consider ideas like re-surfacing the rails in place since your turn around isn't fast).