7mm Mauser

The first mention of 7mm Mauser ammunition in British service occurs in 1904.

In 1902 Chile ordered two battleships from Great Britain, one from Vickers and another from Elswick; originally to be called the Constitución and Libertad, and the ships were launched in January 1903. In addition to the normal heavy armament, the ships were each armed with four Maxim guns, and these would have been ordered in 7 x 57mm calibre as this was the Chilean service round.

In the meantime, Chile had concluded a treaty with Argentina that limited the naval power of both nations and thus Chile was obliged to sell the warships being built in the United Kingdom. After some protracted negotiations Britain purchased the ships for £1,875,000.

The two ships were commissioned into the Royal Navy in early 1904 and renamed HMS Triumph and HMS Swiftsure. When the ships entered British service it would be reasonable to assume that the 7mm Maxim guns would have been replaced by .303” weapons, but apparently this was not the case.

.276 inch Ball Mark I

A Vickers Sons and Maxim drawing Number 10217G of the 7 x 57mm round dated August 1904 exists bearing the title “Cartridge S.A. Ball 0.276 Inch ( Mark I) |N| Small Arms and Machine Guns; HMS Swiftsure and Triumph”, indicating that in fact the 7mm Maxims guns were retained in British service. It would be easy to dismiss the drawing title as simply one invented by Vickers to describe the round, but the fact that it is described as Mark I |N| indicating adoption for Naval service suggests that the title may be official. Further evidence of official British use is provided by an Inspector of Small Arms Ammunition design reference “ISAA 14/48 7mm Mauser Cartridge” appended to the bottom of the drawing. It is possible that this reflects the cartridge originally ordered by the Chilean government from Germany, probably from Deutsche Metallfabriken

The case is a normal 7x57mm Mauser case with Berdan primer. The headstamp is not shown on the drawing.

The bullet is round nosed with a cupro-nickel clad steel envelope and a 98/2% lead antimony core. Bullet weight is 172 grains.

The propellant charge is 37.8 grains of “Rotweill-Blattchen pulver”.

If the Maxim guns and ammunition had already been delivered and fitted to the ships at the time of the Admiralty purchase it is possible that the decision was taken to accept the vessels “as is” and use the 7mm armament at least as a temporary expedient. Later these would have been replaced by .303 inch weapons.

Vickers drawing of .276 inch (Mark I) N

In 1914 once again two battle ships were being built for Chile in Britain. The two vessels were both 28,000 ton battleships named Almirante Lattore and Almirante Cochrane and both were seized on the outbreak of war.

In a repeat of what happened in 1904, the ships were commissioned into Royal Navy service complete with their complement of Chilean small arms, in this case Model 1912 Mauser rifles manufactured at Waffenfabrik Steyr in Austria, again in 7 x 57mm Mauser calibre.

These rifles were issued to second line vessels such as minesweepers and to civilian crews on Defensively Armed Merchant Ships (D.A.M.S.) and 7mm ammunition was issued in British military packaging specifically marked for “Chilian Mausers”

7mm Ball Chilian

"Cartridge S.A. Ball 7m/m Chilian Mauser" was not shown in Lists of Changes and does not appear to have been formally approved. It was manufactured by Eley Brothers.

The case was the normal 7mm Mauser case with Berdan primer. The headstamp was "ELEY 7M/M".

The bullet was pointed with a cupro-nickel envelope and a lead core. The weight was 140 grains

The propellant charge was about 30 grains of smokeless powder.