The 100-ton gun (also known as the Armstrong 100-ton gun) was a rifled muzzle-loading (RML) gun made by Elswick Ordnance Company, the armaments division of the British manufacturing company Armstrong Whitworth, owned by William Armstrong. The 15 guns Armstrong made were used to arm two Italian battleships and, to counter these, British fortifications at Malta and Gibraltar. Origins Around 1870 the largest gun made by UK firms was the 320 mm RML (rifled, muzzle-loading) gun, with a mass of 38 long tons (38.6 t), firing an projectile capable of piercing of mild steel at . This weapon was adequate for the needs of the time, but the progress of gun technology was very rapid. French industries soon made a 420 mm, 76 tonne gun. This led the Royal Navy to ask for an 80 long ton (81 t) gun. Armstrong, the main British artillery producer, began a project for creation of an even larger weapon, an gun, also called the '100 ton'. Armstrong offered it to the Royal Navy, which rejected the gun, deeming it too heavy and costly. Description These new artillery pieces were enormous weapons for their time. Their weight was comparable to that of the much later Iowa-class 406mm/50cal guns, even though their barrels were quite short. They were muzzle-loading guns, with a rifled tube and rigid mount. Each gun required a crew of 35 men, including 18 men to handle the ammunition. The gun was 9.953 m long. The barrel's maximum outer diameter was 1.996 m, which reduced to 735 mm at the muzzle. The construction method of an inner steel tube surrounded by multiple wrought iron coils, was very complex, with several structures containing one another. The internal barrel was long, or 20.5 calibers. The weight of the gun was 103,888 kg, or about 100 tons. Firing was mechanical or electrical, with an optical system for aiming. The gun crews could fire a projectile once every six minutes. Muzzle velocity was 472 m/s and maximum elevation was 10° 30'. At maximum charge (204 kg?) and maximum elevation, a projectile could achieve a range of only 5,990 meters, but at that distance the projectile could still pierce 394 mm of steel (it is not clear if it was mild or hardened). The weight of the mount was: 20,680 kg (mobile mounts with 18 wheels), 24,118 kg (platform) and 2,032 kg (base). The platform was sloped at