303 British ID


I recently picked up this cartridge and am confused as to its identity. I know this was made by Dominion Arsenal, in Quebec.

Originally, I thought it was a blank until I looked at the headstamp. Canada used the a nomenclature system similar to Britain but used several variants during the period of WWII.

Under the British system the letter “Q” would designate a proof load which this cartridge has and an “L” would designate a blank, hence my confusion.

Could this be a proof load Mark IV for a rifle grenade?




I am afraid it is a normal blank Mark V. You are of course correct in saying that “Q” is the code for a proof round, but blanks were frequently made from reject or surplus cases. It is quite common to find (by headstamp) tracer blanks, incendiary blanks etc.

Canada must have had a surplus of Proof Mark IV cases as they were also used for Drill and Inspectors’ cartridges as well.

There was a cartridge for proofing the tail assemblies of No.85 rifle grenades, the QH Mark Iz, but I have never seen one.




Thank you for the information. Your knowledge and expertise on the 303 cartridge is truly appreciated.

I needed a blank 303 for my collection anyway so this works out well.