.303 inch

History

In the early 1880s Britain was about to adopt a .4 inch black powder cartridge for the single shot Martini-Henry Mark IV rifle. At that time it was considered that the smallest calibre lead bullet that could be utilised with a black powder charge was about .38 - .40 inch and in 1882 limited troop trials were held with the new rifle and .4 inch cartridge. Adoption would have been an extremely retrograde step, considering that in 1886 France was to adopt the 8x50R Lebel round using the world’s first smokeless propellant with Germany following shortly afterwards with the 7.92x57mm Gewehr Model 1888.

In 1883 there was a rare outbreak of common sense and trials were halted whilst a number of magazine rifles were considered. Of these, the Lee action with a Burton magazine was thought to be the most promising and further trials were authorised, although still utilising the .4 inch cartridge.

Fortunately, the British military attaché in Sweden spotted an article in a newspaper about the work of Col. Rubin, the commandant of the Swiss national arsenal at Thun. He had been experimenting with small calibre jacketed bullets propelled by a compressed charge of black powder and had achieved some very interesting results. The cartridge was unique in that the case was cylindrical but not bottlenecked, with a brass washer reducing the neck diameter of the case to that of the bullet.

Britain purchased a rifle and 500 rounds of ammunition, which at this stage was rimless. Over the course of the next three years various trials were carried out which eventually resulted in 350 Lee actioned rifles being submitted for troop trials. These were chambered for a rimmed Rubin cartridge in .303 inch calibre, since ironically the committee felt that a rimmed cartridge was necessary for the successful operation of machine guns. In British records Col. Rubin is usually referred to as “Rubini”. Greenwood and Batley Ltd. held the UK rights to the Rubin patents and so manufactured the ammunition for the troop trials, although the Royal Laboratory also manufactured a limited amount. Each of the 350 rifles in the trial was issued with 350 rounds of ball ammunition and 17 dummy drill cartridges. The latter resembled the ball rounds but had white metal cases. Sadly, no examples are known to exist today. Left to right:Original rimless Rubin round manufactured in Switzerland at Thun and purchased by Britain in 1886

Rimmed .303 inch Rubin 1888 Troop Trials round (unheadstamped)

.303 inch Powder Mark I

The troop trials revealed a major flaw with the Rubin case design as the brass neck washer came loose and lodged in the barrel. One rifle suffered a burst barrel in the trials and another a bulged barrel as a result of this. Fortunately experiments had been successfully carried out to manufacture a case that was conventionally bottlenecked after loading the blackpowder propellant and it was this version that was introduced with the new magazine rifle in February 1889. Although minor changes were later made, this case remained essentially the same for the life of the .303 inch cartridge,

The troop trial Rubin cartridges had been unheadstamped (although some Royal Laboratory production was marked in 1888), but the new cartridge was headstamped with the manufacturer’s code and date of manufacture.