not sure what jacketed .357 bullet would be designed to hold together at 2000fps but it sounds like a rather poor idea to begin with. i know of only a few 454 bullets designed to hold together at that velocity and i would imagine it would be a nice varmint round. if ya use a hardcast i'd make sure you do some testing to make sure it stays together at that velocity.
Yup. Can't drive the cast bullet that hard, a common mistake. The bullet I would be comfortable to use at those velocities would be the Punch.
Easier to go with a bigger bore. JMHO.
