.303 inch Blank - Other
A number of other blanks were approved for British or Commonwealth service outside of the normal sequence.
Blank Machine Gun Mark I
Prior to the First World War a blank was required that allowed automatic fire in machine guns, the short Blank Mark V being unsuitable for this purpose.
"Cartridge Machine Gun Blank .303 inch Mark I" was approved to design RL 20682 (and also covered by CIW 5945) in May 1914 and shown in LoC Paragraph 17362 dated August 1915. It was designed to be used in special constricted barrels in Maxim and Vickers machine guns. The design was endorsed as obsolete in August 1927.
The case was unique in that it was bottlenecked about 1.38 inches from the base and had a long thin neck. The case was Berdan primed and the mouth of the case was closed by a strawboard wad covered with beeswax. All specimens seen have normal ball headstamps. The purpose of the low bottleneck was to prevent a ball round chambering in the special constricted barrel.
The propellant charge was 16 grains of Cordite 1/.05 with one wad.
Blank L10A1
By the early 1980s there was a shortage of .303 inch ammunition for use by cadets so supplies of ball and blank were purchased from The Greek Powder and Cartridge Company in Athens.
"Cartridge Blank .303 inch L10A1" was approved in March 1982. Together with the Ball L1A1 they were the only .303 inch rounds to be given post 1954 NATO nomenclature, although why the blank should have been elevated to the L10 position is unknown..
The case was Boxer primed and closed with a pointed rosette crimp and sealed with red varnish. the headstamp was "HXP 82" or similar date.
The charge was about 15 grains of nitrocellulose.
Box label for Blank .303 inch L10A1
Blank Canadian Mark I
At about the same time as the British .303 inch Blank L Mark 9z was introduced, Canada approved a virtually identical blank of their own. Quite why this was done is not known.
"Cartridge S.A. Blank .303 inch L Canadian Mark I" was approved in 1955 but not shown in British Lists of Changes.
The case had a small Boxer primer and the neck was closed with a rosette crimp. There was a neck cannelure which served to secure the over powder wad. They were made at the Dominion Arsenal and the headstamp included the code "L CDN. MK.1"
The charge was about 13 grains of nitrocellulose.