I can most certainly guarantee you you would go wheeling backwards as you fire since the recoil would shift your balance backwards and the Segway would respond by going backwards.
Then you certainly would look like the French army
I may be incorrect but i'd like to see a video with live ammo to see what happens - especially as one of the front guys wheels backwards into the line of fire from the row behind.
You would be much wiser to jump off and start firing.