The .303 British rifle cartridge first developed in Britain as a black-powder round put into service in December 1888 for the Lee-Enfield rifle. In 1891 the cartridge was adapted to use smokeless powder. It was the standard British and Commonwealth military cartridge from 1889 till the 1950's.Best know for use in WW1 & WW2 by British and Commonwealth troops.Your cufflinks come in an ammunition like gift box.Bullet diameter: 13mm