.5 inch Vickers Incendiary & Proof
Incendiary
The date of approval of the "Cartridge S.A. Incendiary .5 inch B Mark Iz" is uncertain and it was not shown in List of Changes. However, it is likely to have been some time in 1943 as this is the earliest date seen in headstamps.The B Mark Iz was essentially a scaled up version of the .303 inch B Mark VII which itself was a development of the so-called "De Wilde" bullet redeisgned by Major Dixon at Woolwich.The flat based bullet had a gilding metal envelope with a single cannelure and weighed 562 grains. Inside was a steel sleeve containing 28 grains of SR365 incendiary composition. In the tip of the envelope was 2 grains of QF composition to aid ignition.Propellant was 142 grains of nitrocellulose. The headstamp included the code "B" and the primer annulus was blue.Right: .5 inch Vickers Incendiary B Mark Iz.
Left; Incendiary B mark Iz headstamped "H/|\N 43 BIZ"Right: Label for .5 inch Vickers Incendiary B Mark Iz.
Proof
Early proof rounds for the .5 inch Vickers appear to have been made by Kynoch"Cartridge S.A.Proof .5 inch Q Mark I" to design DD/L/12699.3 (later NOD 6325) was shown in List of Changes in January 1945 but this was an updating of an earlier approval and replaced earlier designs.The Proof Q Mark I utilised the 580 grain bullet of the Ball Mark I round and had a propellant charge of 140 grains of Cordite size 3 3/4. the cartridge will have developed about 25% over service pressure The case was copper washed (reddened) and the headstamp included the code "Q".Right: Early Kynoch manufactured Proof round without headstamp.
