That part in red is there because at one time only patched round balls were legal to use in the flintlock season, then they allowed maxi balls(conicals) and finally saboted conicals. As far as the any single projectile, it still has to be made to expand on contact because the law says so , what you posted are regulations. What I posted is law. Regulations do not supercede law so you have to read it as, any single projectice so long as it is made to expand on contact. In addition, the 44 caliber or larger still applies as well for the muzzleloader firearm.