To size .321" bullets to .318", I use a "ring sizing die",which I have had for many years.This type sizing die was(still may be)avaliable from bullet swaging die manufacturers,such as Corbin.The die body accepts replacable sizing "rings",avaliable in various sizes, and easy to make in whatever diameter you want.The die is threaded 7/8-14 to fit normal reloading presses, and comes with a punch that fits the "ram" to force the bullets through the die.It's easy enough to make a solid die for one diameter,threaded to fit the press.Now,LEE Precision makes a similar system for sizing cast bullets to be "tumble lubed", but can be used for jacketed bullets(limit sizing to .005" and use appropriate lube).I'm not sure what diameters the LEE dies are avaliable in.To size .003",takes so little force, it is possible the common Lyman or RCBS cast bullet sizing equipment could be used.I have never tried it, but would guess you would need a well fitting top punch and would need to lube the bullets with an appropriate lube before sizing.It shouldn't be necessary to empty the lube reservoir,just don't use it.
RWTF
Keep the ammo and brass. If you don't need it now, you may later, or maybe your great grandchildren will.
Mike