[RERomine]

The speed does appear to be a little low. There is a thread running in the WinSPMBT forum that said a unit's speed should be their speed in kph divided by 3. Since most sources put the speed around 50kph, that works out to in the range of 17.

As for the gun, both fired the same round based on what I found. If the barrel lengths are close and consequently the muzzle velocity, the penetration values should be pretty much the same.