I have often thought about these issues myself.
The mere fact, however, is: there seem to exist no records on them. I think that is was the soldiers themselves that made them.
What litlle we do know is that each gun was delivered together with its bullet mold. Bores used to vary within small tolerances those days. So he who had the mold would have to cast the balls. For paper cartridges, the lug was not cut off but used to fasten the cord.