That .320-165 slug for the .32WSL sounds very like the same slug as used in so many of the old .32-40s.
Lots of old moulds around at gun shows, not expensive.
Getting an original .32WSL back on the range: now THERE is a worthy project! There weren't all that many made and there has been no ammo for years and years (I was gonna say "for a coon's age" but the Moderator might take it amiss!).
On a historical note, too, the .32WSL was the direct ancestor of the .30 Carbine, although the Carbne round ran at MUCH higher pressure. Value entirely aside, personally I would not even try the conversion of a .32WSL to the Carbine cartridge.
Starting with .32-20 seems much safer.
BTW, Barnes (COTW6) gives 12.5/4227 for 1440 ft/sec and 760 ft/lbs with a 165 for the .32WSL: dupes factory ammo.
BTW, .351SL for the very similar 1907 rifle can be made from .357MAX, just in case you have one of those cluttering up your closet as well.
Hope this helps.
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