.5 inch Vickers in Canada

In late 1942 Dominion Rubber Munitions Company, a subsidiary of United States Rubber, set up a plant at Three Rivers to manufacture .5 inch Vickers ammunition. This was apparently principally to produce ammunition for the merchant marine as obsolescent .5 inch Vickers equipments were being transferred from warships to merchant ships for anti-aircraft defence. Warships were re-equipping with 20mm Oerlikon cannon.

Three Rivers started production in 1943 and continued until mid 1944 when they switched to making 20mm ammunition.

In addition to .5 inch incendiary B Mark Iz and armour piercing W Mark Iz they also made some non standard loads including tracer, incendiary tracer and armour-piercing incendiary tracer. Three Rivers, like other Canadian plants at that time, did not headstamp their cases with the specific load but used a universal headstamp and relied upon bullet tip and primer annulus colours for identification. All production was headstamped with the date (either "43" or "44") at twelve o'clock and "TR" at six o'clock.Left: Three Rivers manufactured .5 inch Vickers incendiary B Mark Iz, Tracer and armour piercing W Mark Iz. Right: "Universal" headstamp on Three Rivers .5 inch Vickers rounds.