.4 inch Enfield
History
The history of the .4 inch Enfield cartridge is somewhat convoluted. What started out as a desire to find a new cartridge for both rifle and machine gun ended up as a little used cartridge solely for machine guns which only remained in service for a few years and was declared obsolete in 1898.
In 1879 a Special Committee was formed to consider future armament and ammunition for the Army and Royal Navy. They concluded that any future machine gun or magazine rifle should be chambered for the .45 inch Martini Henry round. All existing machine guns should be rechambered for this round and the Royal navy should adopt a solid drawn case version whilst the army would continue with the rolled case cartridge.
Since the Martini Henry case was heavily bottle necked and the Gatlings proved unsuitable for rechambering the 1879 Committee reversed their decision and decreed that the all new weapons would be chambered for the .45 inch Gatling cartridge and existing weapons re-bushed for the Gatling round.
The planned rechambering for the .45 inch Gatling cartridge was then upset by the separate work at RSAF Enfield investigating a new rifle and cartridge. This work was to consider a new smaller bore blackpowder cartridge in the range of .38 inch to .408 inch, .38 inch being the smallest calibre considered suitable for use with blackpowder.
Royal Laboratory produced a number of .4 inch case designs including two shown on RL779 below, and a cartridge closely resembling these was issued with fifty experimental Martini rifles in 1882. 10,000 rounds of this cartridge were obtained from the Trade.
Further trials were held in the 1881-84 period including at least one design of a .38 inch cartridge, although this does not seem to have been developed any further
Although by now the Martini action was becoming obsolete, work continued on developing a Martini Enfield rifle chambered for a .4 inch bottle necked cartridge. In 1885 Woolwich designed three further tapered designs and one bottlenecked case shown below.
Three designs of .4 inch tapered cases, top left: RL 4978m, top right: RL 4979,
bottom left RL 4981 and one bottle necked, bottom right RL5072.
Both the Superintendent, Royal Laboratory and the Trade stated that tapered cases were more difficult to make and so a slightly modified bottle necked case, RL 5072*, was approved for further troop trials with 1000 rifles.. These trials produced further delays which was fortunate as by now far better rifle actions were becoming available. By 1886 the Owen Jones and lee Burton magazine rifles were both subject to trial, chambered for the .4 indh round, but by late 1886 when the Lee was close to adoption attention was drawn to the Swiss Rubin rifle with its small calibre jacketed bullet and the rest is history.
Left: RL 4979 tapered case.
Some use had to be found for the now fully developed .4 inch round and so it was approved as a machine gun cartridge for use in Gardner and Nordenfelt guns. but was soon declared obsolete in 1898.
Ball Mark I
"Cartridge Machine Gun Ball .4 inch Mark I" was approved to design RL 5368 in September 1887 and shown in LoC Paragraph 5324 dated November 1887.
The case was rimmed and botlenecked with a Berdan primer containing 0.3 grains of cap composition. The headstamp was "R/|\L 87".
The bullet was of a lead alloy of 56 parts lead to 1 part tin and 1 part antimony. It was round nosed with no cannelure and had a white paper patch contained entirely within the case. Bullet weight was 384 grains.
The propellant was about 85 grains of RFG2 blackpowder surmounted by two cloth wads with a beeswax wad between them. Muzzle velocity was about 1570 fps.
Blank Mark I
"Cartridge Machine Gun Blank .4 inch Mark I" was approved in August 1887 and shown in LoC Paragraph 5453 dated May 1888.
The case was as for the ball round but stained copper colour as an aid to identification.
A mock bullet was fitted made of brown paper covered in blue paper with a white tip.
The charge was about 85 grains of RFG2 blackpowder.
Blank Mark II
A blank Mark II appears to have been made but is not shown in Lists of Changes. It is presumed to have had the title "Cartridge Machine Gun Blank .4 inch Mark II" but no record of its approval are known. Surviving examples have the headstamp "R/|\L II".
No other details are known.
Dummy Steel Mark I
"Cartridge Machine Gun Dummy Special for Armourers (Steel) .4 inch Mark I" was approved in April 1891 and shown in Lc Paragraph 6489 dated September 1891.
It consisted of a turned steel cartridge to the profile of the Ball Mark I and the centre was bored out and filled with wood. The base was closed with a steel plug fitted with a rubber ring and the weight of the round matched that of the Ball Mark I.
In November 1891 Lists of Changes instructed that the base should be stamped with an "X" for identification. The cartridges were issued in sets of three to armourers.