Want to make it like a true cannon? Add drop distance, distance based damage, and an ammunition count.

Not quite. Weaponized rail guns are not in production. The US Navy hopes to have a viable platform by 2016 and even then it is going to be on a battleship or heavy cruiser due to the vast requirements of energy. There is little horizontal recoil in a rail gun. The danger is arcing between the rails and as the current is passed through them it wants to push the barrels apart so you need materials strong enough to resist those strong electromagnetic forces. The battleship model will be able to produce a round with a muzzle velocity of around 3,500m per second with 50 mJ of energy.

Being this is the far future those concerns have been addressed and the amount of energy transferred to the round and its efficiency will be through the roof. So what would its muzzle velocity and energy be? More than enough to puncture a tank when its traveling at speeds over Mach 10.

these battlefields are typically not even a full kilometer. the speed of current railguns is Mach 7, or seven times the speed of sound(and this was a test firing at low power, 7 pound aluminum slug)

that is 2.380 kilometers. per. second. it doesn't have enough distance to travel to drop noticeably, and quite frankly, there being any noticeable travel time on those shots is highly unrealistic.

the sheer kinetic force of the impact is what gives it destructive power, railguns do not use any type of warhead. It just uses a heavy chunk of metal fired at ridiculous speed and lets the laws of physics do the rest.

you should be happy your tank even exists after a single hit from one.

Wait till we get fighters and gunshipsthen we will have our revenge