Rapier. I'm well aware of the fact that the .310 Cadet has a larger bore than the 32-20.. It's no big deal. You can buy the proper size bullet mold and RCBS will, or at least they used to, make dies to properly handle the larger bore of the .310 Cadet.
Actually, if it wasn't for the barrel ending up being too thin when converted to .32 Winchester Special, not .32-20, one could have done the same thing with a custom made set of dies.
Hell! I'm still kicking myself for passing one up in .357 Magnum rebarreled by P.O. Ackely.

I won't make that mistake the next time one shows up.
Paul B.