Hammering the ball into the bore was long gone by at least the first quarter of the 18th century, i.e. the early 1700's. If a person had you, the modern person, hammer a ball into a jaeger rifle from that time period, what happened was they learned of the myth, and assumed that was the proper procedure...and were lucky the ball flew straight at all.
German Jaegers are well documented as using patched ball in the 1750's and the AWI here in North America.
The patched ball was a German/Swiss invention as far as we can tell from journals of the time period from the late 16th century...yes the 1500's, and from what early historian report, though they don't always cite a source for their conclusions.
It appears, though unconfirmed, that a Swiss fellow first came up with a rifled barrel. First, it's tough to tell if he was the actual inventor, and second in those days Switzerland, Austria, Germany, and Czechoslovakia were a mish mash of tiny principalities..., so not only did folks not identify as "German" or "Swiss" etc, and more like, "Ansbacher" or "Hanauer" or "Kesselman", you have the problem of whether or not the location where an invention is documented is the same as the origin of the inventor. So if an invention like rifling was documented in Vienna, but the inventor was from Florence, is the invention Viennese or Florentine ?? Further there is debate that the first barrels were "grooved" aka "straight rifled" [oxymoron term] to facilitate less cleaning and easier loading..., perhaps with the ball forced onto the rifling after a wad was added between it and the powder. When then did the twist come into play?
The hammer for the British Baker, a rifle of the Napoleonic Wars, was to clear the rifle in combat. If the rifleman got a ball jammed in a dirty barrel, he could force it down upon the powder and then shoot it free. It was not part of the normal loading procedure. The Baker had a very slow twist rate 1:120 to facilitate loading a dirty barrel in short time, and to give enough spin to stabilize the ball out to 300 yards. Accuracy was not great..., it was meant to take an enemy soldier or officer out of action on a battlefield. So if one aimed at the fellow's head at 300 yards and lobbed a .600 caliber ball into his shin...the job was accomplished. It was not meant for hunting. The Germanic Jaeger Rifle and it's American stepson, the Long Rifle were hunting weapons used for war.
LD