First a silly question - when is the last time you removed the chuck and serviced same?
I find that most of my customers never do this and that is half their problem.
More specifically, is it your jaws that are worn, or the chuck components? Or, is te chuck so full of crap that you cannot chuck anything true?
Either way, I typically try to clamp a slug in the master jaws to bore my top jaws. Typically, they will be set back from the top tooling and you can true them up.