I just tried something in a .50 caliber flint side lock barrel that has a removable breech plug that would be considered a sin to traditional black powder hunters. I pushed a .452 300 grain Hornady pistol bullet down the bore on my usual pillow tick patch lubed with Hoppe #9 bp lube/solvent.
When I attempted to move the projectile in the bore by a good hard bumping of the muzzle on my carpeted floor it stayed put. It had loaded real nice but not too snug with the .018 cotton patch. I got my calipers out and checked the thickness of the petal on a MMP short black sabot and it read .025. So; now I'm thinking maybe I don't need these darn plastic sabots anyway; I hate the dang things. I can't wait to see if it's accurate. It's a 1/28 twist GM barrel. Bumping up the patch size a few thousands at a time just might produce a decently accurate load. I think it just might work if it were snug enough to spin the bullet. Since it's copper it won't bump up like a lead ball does.
So now as I am thinking about this a little bit more I get to thinking that ok a 1/48 or maybe even a 1/66 twist with traditional groove depths of ten thousands might shoot the pure lead 240 grain .452 pistol bullets in a cloth patch. It should grip and spin a little bit better than the .005 groove depth of the fast twist barrel and the shorter 240 may just stabilize pretty well. No leading either.
Bless me for I have sinned; but for some reason I feel good about it. LOL