Damage to a town does contribute to captures (even if more damage is required).
Unless a bombing of a town a certain time before the main operation begins leads to the town buildings being down out of sync.
But with some attention on part of the town milker, that can be avoided. Just don't bomb frontline towns that are possibly coming under attack not immediatly, but in the not so far future (exact time frames depend on current enemy downtimes governed by their city).
For the original question, I don't think it's possible without rearming. Personally, my best displayed damage was only at 59,278 in a 12x1k town milk run in 2013. (Score damage points are a different matter, but those two values are only very loosely connected anyway).
