Whitworth muzzle-loading mountain gun
During the War against Russia, the Turkish chasseur battalions were reported to be equipped with a 3 pdr Whitworth muzzle-loader gun, but it is not easy to identify it. Angel Angelov in his “Материалъ за история на българската артилерия” published in the Артилерийски преглед says that its technical data were almost the same of the Russian 3 pdr mountain gun, except that it was a muzzle-loading, and not a breech-loading gun. No additional information was provided by the Bulgarian sources, except that its calibre was 6cm and its range only 700 m. This was the only one muzzle-loading gun employed by the Bulgarian artillery in combat.The first big question concerned the calibre. Due to the particular shape of the Whitworth rifling there was a great difference between the maximum and the minimum diameter of the bore. This means that the same gun could be regarded as 60.2mm, 57.53mm or 54.86mm – like the 9 pdr breach-loading field gun tested by the French Army in 1873 – according with the point chosen to measure the calibre. Nevertheless, till now I have been not able to find a 6cm Whitworth muzzle-loading mountain gun.A 3 pdr Whitworth mountain gun was adopted by the Spanish Army, but its calibre was only 45mm, while the 2.17 inch (55mm) Whitworth gun employed by the Confederates in American Civil War was described as 6 pdr, but it was a breach-loading field gun too heavy (771 kg) to be identified with the Turkish gun employed by the Bulgarian Army. Finally some 2 pdr Whitworth mountain gun, also referred as 2½ or 3 pdr, with a calibre of 43mm, were employed by the Free State of Orange against the British Army during the Boer Wars. In 1867 that 2 pdr gun had been on display at the Paris Universal Exhibition, where it was described as “designed to meet the want of a light field piece adapted for easy and rapid transit across mountainous or broken country, or for accompanying the evolutions of detached bodies of troops”.Also the range showed by the Bulgarian official history of the Serbo-Bulgarian War sounds strange, since the Whitworth guns had usually a greater range than the contemporary guns.However a letter written on 21 March 1879 by the adjutant of the Chief of Staff of the Bulgarian Territorial Army stated that among the Turkish war trophies received by 16th Plevenski battalion there were:– 6 4.5cm Whitworth steel mountain guns;– 6 iron carriages with elevating gears for them;– 6 wooden limbers;– 14 pack ammunition boxes with 455 shells;– 41 case shots;– 15 pack saddles;– 2 spare wheels.I think that these might be the Turkish Whitworth guns briefly employed by the Bulgarian Army. At any rate, I added the data of the 45mm guns that are fairly sure. This supposition is confirmed by an article published by the Военен Журнал in 1889 that I have recently discovered. It stated that the Bulgarian Whitworth gun had a calibre of 45mm and its description and the data of its ammunition agree with what I found for the Spanish Whitworth gun. It is highly probable that the wrong indication of its calibre originated from a confusion with the Broadwell mountain gun, which actually had a calibre of 6 cm.By the way, in the Military History Museum in Sofia a “47mm mountain gun – Serbo-Bulgarian War” is exhibited at the entry of the building. Unfortunately it is placed in a sort of diorama and I could not have a close look at it. It cannot be the Whitworth gun, since, as far as I could see, it should have a breech-block, but it would be very interesting to know its calibre, the length of the barrel and so on, in order to identify it.The Whitworth guns were manufactured from “homogenous iron”, an early kind of steel. Their rifling was peculiar and consisted of a hexagonal bore with rounded angles and a uniform twist into which a precisely shaped shell, with negligible windage, fitted. To ensure complete sealing a greased wad was placed in the rear, between the projectile and its black powder charge. The charge was enclosed in a cloth bag and was ignited by a copper friction tube. The barrel could be mounted on a small field carriage, which was limbered like a field gun, and on a special mountain carriage, which could be disassembled and packed on mules or fitted with a wooden trail shaft to be pulled by horses. Both kinds of carriages were made of iron. According with Angel Angelov, the Whitworth guns employed by the Bulgarian Army in 1885 had 3 ammunition boxes per gun, with 34 shells each.In spite of their precision and small dispersion, the Whitworth guns were not able to become popular, since the manufacture of its bores and its projectiles was very complex and prevented a mass production. The shells should be accurately planed to shape, a more difficult process than turning. Furthermore the bore should be kept scrupulously clean at all time, otherwise the projectiles were inclined to jam, especially at close range.
