Lazs, would you mind sharing where your info on the British Martini-Henry used in the Zulu wars comes from? According to my info, Martini-Henry MkI and MkII (which are most likely what they would have been using in the 1870's - 1880's) were a .450 caliber rifle. There was also a carbine version, which used different (lighter) rounds, but still same caliber. In a pinch you could use either bullet in either gun, the one designed for the infantry rifle was just a bit stout in the carbine length gun (lots of recoil).
Problems with the early Martini-Henry were more based on the ammo available, not the gun itself. The original cartridge cases were made of a thin sheet of brass rolled around a mandrel, which was then soldered to an iron base. These cartridges were assembled by the orphaned children of British Soldiers, and were relatively cheap to produce. They were found to be vulnerable to being easily damaged, and produced inferior muzzle velocities. Later, the rolled brass case was replaced by a solid brass version which remedied both of these problems. The infantry rifle fired a .450 caliber, 480 grain bullet with 85 grains of black powder. The cavalry carbine fired a 410 grain bullet with 70 grains of black powder, making it very similar to the more well known .45-70, with similar ballistics. The Martini-Henry would not have (IMO) had the same effective range as say a Sharps or Springfield .45-70 because of differences in the lands and grooves, but thats just my opinion. I dont have any long range data on the Martini-Henry to back that up.
