I've finally decided to splash out on a brand new 3-jaw chuck for my lathe; I've picked up 3 2nd-hand 3-jaws at various times; and, frankly, they're all rubbish; chucking a bar, then re-chucking it, and I get anything up to 0.010" TIR. Not good. I've been getting along with a 4-jaw independent, but there's wear in that too & I have to shim one of the jaws to prevent it holding the workpiece at an angle.
So, anyway, new chuck.... I'm aware I will have to make a backplate; my question is, should I get the 200mm chuck, or the 250mm for an extra £30? The next size down (160mm) doesn't have any soft jaws available, which rules it out IMHO; and the next smallest is smaller than my spindle nose. The biggest bar stock I tend to use is ~2", although I do have some plans to turn a piece around 9.5-10" diameter (but I can always use the 4-jaw for that, if I have to). The lathe spindle will only pass ~45mm stock, so the size of the hole in the centre of the chuck isn't really a consideration.
Is this a case of bigger basically being better? Or should I save the 30 quid by going for the smaller one?