The Westley-Richards "Monkeytail" carbine was the main arm carried by the Boers in 1880/1881. It could be used as a breechloader with a paper cartridge or as a muzzle loader with loose powder. Ignition was by the hammer striking a percussion cap. The octagonal Whitworth rifling gave it accuracy. Because the Monkeytail did not need imported brass cases, it was popular for a long time, the OVS purchasing 500 carbines as late as 1883 even though the Snider, Martini Henry etc. had made it technically obsolete.
Fortunately, to own a Monkeytail in the UK you do not need any certificates or any other papers. There are three Monkeytails coming up in the next auction at Holts in June 2021, all "correct" for the Majuba period; lots 501, 512, 524