Power Supply
Take a powerful, lightweight (relatively speaking), gas turbine out of an MBT and hook it up to a large generator (technically, an alternator).
Power the wheels (or treads) within individual motors (which can also act as braking generators).
Time to fire the rail gun? Keep the gas powered genny running, hit the brakes to generate additional surge power, and funnel it all to the rail gun.
Once fired, stop breaking and redirect power back to the propulsion motors.
All you need, now, is for the fuel truck convoy to not take a wrong turn.
Biting the hand that feeds IT
