I know I'm late to the party, but having read this thread, I eventually ordered the Warco 5c chuck with built-in D1-3, with the intention of adding a back plate if runout was bad. Well the one I recieved had a runout of more than 0.002" on the inside tapered part of the chuck – much higher than I'd hoped.
I tried a couple of positions and made sure all the mating surfaces were spotless, but just couldn't get lower than 2 thou.
I thought about returning it but I can't resist a tinker, so took it apart. The front separates from the back at the hole for the chuck key.
The rear part has an alignment ring ground into it. So it was an easy job to mount it directly on the lathe and turn the ring down slightly:
I took 0.005" off it, to give a bit of wiggle room for future adjustment. During this process, I found that the inner ring with the through bore was out of true by a lot more than 2 thou – nearer 20 thou – so I turned that to be true to help balance the chuck.
Stuck it back together and a bit of judicious use of the rubber mallet, and now the runout is down to a couple of tenths. I'm thinking of putting some threaded holes in the front part and some grub screws to make the runout adjustable with a hex key. There's not a lot of room for error though, as the alignment ring doesn't project that much.
I haven't yet measured the runout with a collet installed, so I'm not sure how good it will be a couple of inches from the chuck.
If I could justify the expense of a Bison, I'd definitely go down that route, but the Warco one now suits my needs, and at least it's possible to fettle it.