I just put air to it and shot it. Holy $4!7 i forgot how much i loved that thing. it shoots quick and smooth but my only gripe it that it went through a 3000/40cu tank in only like 3-400 shots. What gives? its all stock minus i took out the trigger return spring

so what can i do to fix it? Also it seems to be leaking a little from one of the ports on the back left side of the gun. It has sat for a while so i assume that it needs new o rings. anybody sell an o ring kit?