Just remember the patch is doubled, and should be a hair larger (patch+ball+patch) than the bore- squeeze fit. You may need to try some combinations to see what your gun likes- and check the maker's instructions.
For a muzzleloader, I use pure, dead soft lead. Scored 150 lbs of dental xray film pouches for 25 cents at a govt auction some years back. Will keep me casting Maxiballs until I am 99. Then I need to get more.
What we have here is... failure- to communicate.