The gun made 'famous' by Kipling's poem The Screw Gun was the RML (rifled muzzle-loading) 2.5-in (63.5 mm) jointed mountain gun which fired a 7-lb (3.17 kg) shell. For easy portability the piece was made in two parts which screwed together, hence the name. It was adopted by the Royal Artillery in 1879, and continued in service throughout the South African War. It was not adopted by the New Zealand Forces. The gun performed satisfactorily according to 19th century standards, but there was nothing remarkable about it.
Kipling may have made the gun 'famous' to readers of his poem, but it was far from popular with the unfortunate Gunners who manned it in South Africa. Although cordite had been introduced in 1891 cartridges for the screw gun were still filled with gunpowder which produced clouds of white smoke making concealment from views impossible. Since open sights were the only means of laying provided, the layer had to be able to see his target, so cover from fire was also virtually impossible to achieve. Thus Boer riflemen made excellent practice on gun positions.
So while some find Kipling's poem inspiring others find it nauseating.