Use your little brass hammer to beat it into submissive center
If you are turning for example a 1" round stock down to .750, you will not need to spend a lot of time getting it perfect (Unless your name is Murray
), just close and the offset will soon disappear as you cut it. In this hypothetical example it could be off as much as .250 and you still would end up with your .750 shaft. But I am sure you can get it a lot closer then that
You can also eyeball the jaws to see if they are oriented equally in the slot they slide in, there are normally circular grooves on the chuck face, I use these for the rough set.
After a while you will be amazed how close you can come just eyeballing it.
Another edit:
BTW, get in the habit right now of
not leaving your chuck key in the chuck for any reason what so ever, I.E. never and no loose long sleeve shirt cuffs to get caught up in the chuck. Always be thinking how this sucker can hurt you.