I agree with
HerrKaLeun that sanding the frame is probably not a good idea unless there are obvious defects. Was it a new or used frame?
You could probably build the shell back up slightly using epoxy.
I'm seeing that there is a 68mm and 73mm BB30 standard.
PF30 comes in 68, 73, and 86.5
Perhaps you need to buy a wider BB shell.