I like the idea. It should have a refire rate of 1 shoot every 3 seconds or so.
Speed should be in the order of 2000-3000 M/S and range should be arround 800m.
For the visual effect, if we can create a new one, ive seen one on a game called Tachyon: The fringe. The effect is the one of the...... railgun :)...
(If you find any mistake in my English, please let me know via a PM)
(Really, I speak terrible English, so please, tell me if I make mistakes. I'd like to improve it a bit )