The only difference between here and the ISS is gravity. You'd just have to get used to a BB not arcing. Doesn't matter, the space station would be pretty close range anyways. There would still be air resistance, and the BBs come out of a AEG at the same old regular AEG speed. I don't think one would even fire in a vacuum. A GBB might, if it hadn't exploded in your hand first.
Anyways, it is purely academic. But an amusing conjecture, nonetheless.