I would love to try to replicate this original Nessler cartridge, I kind of simplified it with the .660 slug. The .680 slug leaves very little windage for any paper, the wrap would have to be .005 or so. The white cartridge I made in the above posts is super fragile, as in it would probably tear under rough handling in a cartridge box. The paper, I believe, would probably fail during the trip down the pipe. You would almost need Onion paper.
I saw in earlier posts that the Balle Nessler used in testing was .660 but must have had a thicker skirt.
The Eras Gone NC Nessler is .680, I like the idea of the guy who made the mold, that they were for .71 muskets ,in a paper wrap .
I can find no info on the Chace Ball. It was never adopted and only that Chace fired some over the Potomac for Lincoln (that must have been nerve wracking , having the President himself watch you fire an experimental bullet) but no drawings exist. The only originals are likely 10 feet down in the dirt near the Potomac. Was the Chace ball in a paper wrap? Someone has to know......or not.
I honestly can't think of any way to get a paper wrapped .680 Nessler down a .69 bore that's fouled, and some Nesslers mic to .678-.680. I've seen French muskets listed as ".70" in American Ordnance Tests....did they just round up to a nominal bore size or were they .70's? In that case, a .678 or .680 Nessler makes sense for French and Belgian use.
Given that these were used by at least 4 nations for 10+ years there was probably changes made to them. How the NC Nessler was a .680 is baffling other than the .71 musket idea.