I know nothing about railguns, but if they are supposed to launch the projectiles with magnetic force then why do they need to impose any wear on its barrel at all? Couldn't you build a railgun where the projectile never even touches the barrel, being kept at the center by the same magnetic field that accelerates it? Or are we talking about the wear imposed by the magnetic field itself?
If I recall correctly, a "railgun" per se is one that uses the projectile to conduct electricity between the "rails" that direct said projectile. So there's contact, between parts moving hypersonically relative to each other.
It would seem that even without contact there's wear issues with both force exerted on the rails or coils from the magnetic forces and also with creating plasma as the projectile exits?
