It would be a great battlefield rifle.
I wouldnt be at all surprised if the first few examples were worse than useless.
Every new technology suffers from a certain amount of failure when it first enters the wilds of the real world.
Considering the messiness of the battle field it is hard to imagine the first battle tested electric battle rifle being an unalloyed success. Water, sand, mud, ice all are enemies of electrical equipment and all are found on the battle field. But given time and the ingenuity of Americans they will be defeated and the American soldier will have a rail gun battle rifle.