I have recently bought a Sanou 5" six jaw and it's operation is smooth as silk straight out of the box, despite it being a cheapo.
Baz has the right idea, strip down, and because all jaws and screws are the same on an independent, try swapping them about a little. Usually it is just a bit of tight machining tolerance that causes the problem and a tiny bit of fettling on razor sharp corners with a very fine Arkansas stone and some slideway oil soon has them running perfectly.
BTW, almost every one of my chucks (loads of them) are of far eastern origin and I haven't a bad one amongst them, all very accurate and smooth.
If you don't try it, you will never know if you can do it!!
Last edited by Blogwitch; 03-18-2017 at 09:19 AM.