The Arrow of Death is still an arrow correct? In which case it is still ammunition. If the arrow of death were to hit/kill 1 creature it will be destroyed and/or rendered useless (so there are non currently in existence). You then use Arrow Eruption to duplicate the exact arrow you used to kill someone last round and launch it at a different target. There by giving you 2 Arrows of Death back to back.
I'm just wondering if I am following that line of thinking correctly or if I missed something that would make this not true.