Armstrong gun

In 1854, Armstrong approached the Secretary of State for War, proposing that he construct a rifled breech-loading 3-pounder gun for trial.

Armstrong's guns used a "built-up" construction, comprising a central "A" tube (initially of wrought iron, and from 1863 of mild steel toughened in oil) holding the bore over which were shrunk several wrought iron coils which kept the central tube under compression,[1] a breech-piece, and a trunnion ring.

This spin, together with the elimination of windage as a result of the tight fit, enabled the gun to achieve greater range and accuracy than existing smoothbore muzzle-loaders with a smaller powder charge.

On top of each gunpowder cartridge was a "lubricator" consisting of tallow and linseed oil between two tin plates, backed by a felt wad coated with beeswax and finally by millboard.

The wall afforded very little protection to the Tartar gunners, and it was astonishing how they managed to stand so long against the destructive fire that our Armstrongs poured on them; but I observed, in more instances than one, that the unfortunate creatures had been tied to the guns by the legs.

Armstrong guns were used against British and Indian troops during the Second Anglo-Afghan War in the Battle of Charasiab, in which Howard Hensman describes six being captured by a combined Anglo-Indian expedition under the command of Brigadier-General Baker.

This was adopted by the Government for the first generation of rifled muzzle-loaders, termed "RML", together with Armstrong's built-up wrought-iron construction method, which was considered sound.

It was a major supplier of modern "BL" guns to the Royal Navy, British Army and the world export market until the 1920s.