For nice surfaces especially things like metal water ect. having a high poly count will allow you to get the varience you need at the moment the way you gun is esablished maya will not render the metal acuratly no matter how good the set up. Things are calculated from per poly basis so one poly means one calculation. Smooth before you render and youll be able to see a big difernce in image quality. That does mean fixing the trilliongon you made, I wouldn't want to do that. Good Luck.