Because the projectile is accelerated using electro-magnetic energy a recoil in the classical sense dose not occur. Rather there will be an energy transfer from the source of the magnetic field within the gun to the projectile and vice verses.
I'm not sure what you mean; but please do the following thought experiment. Put a railgun on a raft with a flexible connection to power. Is it your contention that if the railgun is fired that the raft will not move?
In technical terms, the recoil caused by a gun exactly balances the forward momentum of the projectile and exhaust gasses (ejecta), according to Newton’s third law. Because rail guns do not use a rearward propellant and all the momentum is transfered between the rails (which surround the ‘barrel’)and the projectile the transfer of that momentum to bring the equation back to zero does not constitute recoil in the classic sense.