Those are bullets made for the 32 Winchester Special. They are also for the 32 Remington (SemiAuto Rifle).
Both of which I load as well.
FWIW,,the 32Rem is supposed to have a groove diameter of .319/320. But I haven't slugged mine to find out. These 321 jacketed bullets work fine. 8mm Numbu bullets (102gr LRN)do as well for plinker loads.
I've used the 32Win Spec bullets in a .318 8mm Mauser cal (88 sporter) and found that if you back off on the loads,,use minimum or near minimum loads in 8x57, they are more accurate.
Perhaps the bullets themselves are of a lighter weight jacket or overall construction and they just can't be pushed as fast. Maybe it's just their shape,,I don't know, just guessing.
But that's my experience.
Perhaps the thinner jacket .321 dia collapses to the .318 groove much easier too than a heavier built one. Maybe too easily and it gets roughed up a bit causing poor accuracy when pushed along too fast.
Again just my guesses.
I use standard 8x57 (.323) loading dies.
Neck sizing only. Plus I do not expand the neck.
The expander button is removed and replaced with one from a 25cal (IIRC) so it doesn't do anything but carry the decapping pin.
The sized only neck has what I feel is perfect friction fit/pull for the smaller dia bullet.
I'm sure that would vary die to die.
You could always just reduce the dia of the .323 expander button too.
