Gareth,

Indeed the "Twelve Apostles" date from the 17th Century and are possibly (no evidence) the first use of premeasured charges for firearms, but I've always assumed this song to be later {1}. I suspect the term "charges" in the song refer to the loaded round rather than any particular means of loading the weapon, however the powder is carried, the weapon is still "charged".

On the subject of Pyrodex (mentioned in a couple of earlier posts), I understood that it was generally used in ammunition for cartridge weapons which were only "proofed" for black powder (example, the pre-1900 Webley revolvers), but NOT for muzzle loaders.

Walrus

{1} I tend to associate "apostles" with muskets and carbiners rather than pistols