From 'Surgical Experiences in the Zulu and Transvaal Wars by Dugald Blair Brown F.R.C.S.
"The guns possessed by the Zulus were chiefly our old pattern ones, with the Tower mark upon them of 1847 and about that date. After the disasters they became possessed of immense numbers of our modern rifles [many later sold on to Boers]and ammunition. However, with very few exceptions they were unacquainted with their use. In many instances Martini-Henry bullets were found in the cow-hide pouches around their waists, cut in two and separated from their usual cartridge combinations, the powder being doubtless mixed with their other in their cow-horns which served as their powder flasks. The majority of their bullets consisted of spherical masses of lead. generally hammered into form and not moulded. Others were very roughly shaped and had a rough prominence on them, while a few were very carefully made. The latter were generally surrounded by a piece of cloth sewn accurately on them."
My opinion is that this shows how Martini-Henry ammunition was used to supply the Zulu muzzle loaders. It also suggests how round balls were used for accurate shooting in their rifle muskets by virtue of a sewn on patch. Possibly learned from Brunswick ammunition in the Kaffir Wars?