Lathe milling table

[Toolmaker51]

C-Bag's having trouble in the kitchen; burning all kinds of food.

......................Meanwhile in recommendation and IMHO; sometimes NSHO as well....................
While lathe spindles have all kinds of rigidity; 3 jaw chucks on hardened shanks I'd question. Just like never run taps in drill chucks, jaw faces too difficult to restore, especially if serrated.

If a chuck MUST be used, invest a little time on mild steel bushing; collared to sit on jaw face, bored to size, [not just drilled and reamed] tapped for setscrew(s) to engage Weldon shank flats and split one side for compression - almost a collet. Close up jaws, then setscrew. The collar will aid retention of concentricity at far end of cutter. If a Set-True chuck, dial in un-ground shank for runout. 4 jaw even better.
Fact there is HP for shell mills pretty much validates it.
If anyone wants a drawing, please respond so.