I use the machinist's vise with a swivel plate, rubber pads in the jaws and a cross test level. Throw in a few jacks and clamps where needed to firm everything up.
I put foam rubber in a 6" Kurt vise and get the tool bit rotating as fast as the mill can spin it.
And of course, do not tighten so much the stock cracks.
Keep the tool force low, and the stock position will not deflect much.