The buck has pointier jaws, allowing it to close quite a bit more than the Bison. If you don't have a collet chuck and plan on turning small diameter rods, then the Buck is the better choice.
I have a Bison Set-Tru 3-jaw and love it.
BTW, any particular reason why you're going with a 6-jaw? My 3-jaw has blunt jaws, but the nature of 3-jaw chucks is that they close pretty far regardless. |