Man, I have been arguing in use of that gun during oracle phase for past 10 pages here. Trust me, use that thing on oracles and thank me later.
Just be usre to stand under it when you do it, don't try to snipe from afar. On hard it kills oracles in two shots when gun is leveled up.....
To give you basic idea, I always kill first 3 oracles with in seconds of porting by my self on HARD (soon as they spawn, they die) while my other two team mates duke out with snipers/praetorians. Id kill all of the oracles but I would run out of ammo real fast that way, plus I am not that greedy to keep all that booty for my self