Fot the British infantry it's clear, the .450 Martini Henry rifle Mk II, introduced in 1875. The cavalry had the .450 Martiny Henry carbine, pattern sealed on 26.11.1877 , a much shorter and inferior arm. In some movies we saw carbines with the infantry.
The problems start with the Artillery. Empress ZWB 28 includes a bombardier, stated as carrying a Martini Henry carbine. But the RA Martini Henry carbine was not ready in 1879, only on the 21.7.1879 was the artillery carbine (A.C1) approved for horse and field artillery. At Isandlwana the N/5th RA had the old Snider carbine. Anyway only 12 carbines per battery (or 2 per gun crew), the NCO's got Revolvers like the officers.
The mounted colonial forces did not get Martini Henry carbines but the Swinburn Henry. Same ammunition but a different mechanism. Fortunately they look very much like the Martini Henry so there is no problem with the 28mm miniatures.
The NNC mounted units got them too. But there is no official document about that. The white colonial units had Snider carbines before they changed to the Swinburn Henry carbine. We may assume that these stayed in South africa. So we can not be 100% sure that not some of the mounted NNC had this arm. That some carried spears in addition is a little strange but without bayonets there was reason for that.
The NNC foot got only a one in 10 gun equipment. Most state old Rifles = Enfields. But 1877/78 the Government produced a large number of smoothbores, looking like the 2 Band Enfield. Intended for use by native forces. Again that is more important for rules than makers since they look alike.
The Zulus should include an assortment of muzzleloaders and Sniders before Isandlwana. Then Martini Henry Rifles and Swinburn Henry carbines. For a plastic range I hope for both otions

