What affect does the material used for a projectile in a coilgun have?

I'm looking to make a coilgun and would like to know if the choice of material for a projectile affects the maximum force/ velocity per shot for a given current? For example; would using a metal with very high magnetic permeability, ie mu-metal or hyu-80, mean that a greater velocity could be produced compared to a steel or iron projectile of the same size/ weight under the same conditions?