Actually hblair.. one thing I am prone to do is to fly attack and take up ord to defend a base from GVs.  Unfortunately, they ordinance isn't always needed in that scenario.. so I jettison it.
I'll also jettison it before wasting it on targets at a base that have not strategic value once its hangars and acks are down.  I won't kill fuel dumps, barracks or any other structure that may be needed at a later date.  Sometimes we do kill the ammo bunkers if we don't have enough ord for the BH.
So there:P
AKDejaVu