First, I know that this isn't the perfect place to post my inquiry, but it's the closest to it that I could find. Mods should feel free to move this thread wherever they believe most appropriate.
My question is about reloading discarding sabot (BRI style) slugs in shotgun shells. I know that such a thing involves neither black powder nor paper-patching. But what can be done with BP can (usually) be done with an equivalent smokeless propellant. I know that paper-patching is not the same as a discarding sabot, but both do many of the same things, except that paper-patched bullets usually travel down rifled barrels, while DS slugs usually do not.
The BRI style (or similar) slug is what I'd like to investigate. I know that BRI probably doesn't exist anymore, and the rights to the slug were sold to someone who redesigned it and offered (offers) it commercially. Various manufacturers offer them, but right now, such rounds are unicorns. At $5/round commercially, when and as available, my interest is also in economy.
So my question is: Can DS shotgun slugs be safely and effectively reloaded by the private reloader, and are necessary components available? I suspect that any custom mould maker could machine one for the projectile. For the life of me, I do not know where to find nor how to fabricate the cotton DS wads. Could a shot cup or the "fingers" therefrom be used in place? I've also contemplated "dunking" the slugs in PC coat then sizing to appropriate diameter.
Any information, experiences, thoughts, or opinions are welcome.