The Story of "DI" ( Defence Industries) is an interesting one.
It was set up in 1940-41, to manufacture ammunition, using Boxer primers, rather than the common ( British) Berdan primers used in the Government ( Dominion Arsenals Canada series of Plants).
For this, the technical assistance of Dominion Cartridge Co (Canadian Industries Ltd), was engaged, because they had been making Boxer primed Sporting ( and some Military Contract) ammo since before WW I.
A completely new Plant was set up in Montreal and became "DI"...because of Shipping difficulties across the Atlantic, the Machinery was acquired locally or from the United States.
The Plant produced .303 to Aircraft use standard, usually found in 48 round packets or belted, in Ball and Tracer and Possibly other types, and also 9mm. The Question of 7,9mm production for China is disputed hotly on these and other Boards, as is the question of Covert 7,9 and 9mm ( the "7,92MM" and "9MM" with wartime year dates.). Lots of .455 and .380 for revolvers sort of rounds out the wartime production.
Dominion Cartridge had made .30/06 in 1918, but it is not certain if DI made any .30/06 during WW II.
At War's end, DI was terminated as a Gov't/private Plant, and the machinery dispersed to both DAC ( Govt. factory) and back to Dominion Cartridge Co.
DAC was making Boxer primed .30/06 in the 1950 & 60s.
With the demise of the Gov't Factories system in the 1970s and 80s, IVI ( Industries Valcartier---Valcartier Industries) was formed , and began supplying the Canadian Gov't with all its Military ammo requirements on long term contracts. The use of the Bi-lingual
( French-English) name stems from the fact that in the late 1970s, to placate the Quebec Independance movement, the Gov't of Canada decreed that all Company Names, Product labels, etc in Canada, or imported for use in Canada, be Bi-Lingual in French and English. Companies based in Quebec Province would have French first, and English second. The other provinces vice versa.
This sort of dates the appearance of the IVI headstamp.
As to the use of the triangular primer crimp, this is just a factory variation; depends on the primer crimping machine set-up used. Most DI ammo used the Ring crimp; the triangular crimp seems restricted to 9mm, although I have seen 9mm using the ring crimp as well from DI.
Other ( Canadian ) Collectors will have more information about the Histories of DC Co., DI, DAC, and IVI, with complete Location and Timeline information. Other DA factories during WW II were DAQ and DAL...
Hope this general history is of use...please correct if there are boo-boos.
Regards, Doc AV