Paper is no more abrasive than a linen or cotton patch if you do not use the kind that has clay fillers in it. I have fired thousands of paper-patched bullets from modern rifles and only do the polishing thing deliberately with copier paper.
I don't know about round ball in paper for a rifled bore, I doubt it would seal or be accurate.
If you want to use hollow-base bullets, it is a simple matter to wet-patch the bullet with a long patch and tuck the tail so that the tube extends far ahead of the bullet tip. When dry, dip the entire bullet end up to the ogive in melted wax/oil lube and let harden. Then pour your charge into the tube against the nose of the bullet and fold the tail. To load, tear the tail, pour the powder down the muzzle, then turn the cartridge around and thumb-seat the bullet flush and tear off the remainder of the patch flush with the muzzle. Ram the bullet, prime, and fire.