Did the Canadian ammunition factories make .45 ACP ammunition for their own forces or foreign forces during WWII or Korea?
Defence Industries made 45 ACP in WWII. DI hs.
The full headstamp of the .45 ammunition made during WWII by Defence Industries Ltd. was “DI42 45 AC.” They made it for themselves, and some went to England as well. Only the “42” date is known. Aside from ball, there was also a Helmet Test Load with red tip. This can easily be mistaken for tracer by collectors. Of course, at the time, it was not meant for field use by troops, so there was no danger of that confusion, with the boxes clearly marked for the purpose of the ammunition.
There was also a red-tipped tracer, but this is a special instance. The ammunition was originally ball or new primed empty cases. The bullets were U.S. or Canadian made 230 grain ordinary ball projectiles converted to tracer in England, leaving the final bullet weight at 210 grains. The bullet is secured in the case by four, stab-type neck crimps. This was likely done because the original crimp, in the case of converted live ammunition, was destroyed in removing the bullets from the cases. Very little of this ammunition, approved for service in January 1943, was actually issued to troops. The headstamp is the same as the Canadian Ball - DI42 45 AC. Ball, tracer and helmet test rounds with this headstamp all have one case cannelure, and a copper primer cup sealed with purple lacquer.
The Dominion Ammunition Branch of Canadian Industries Ltd. made the .45 cartridge commercially as well, and two headstamp letter sizes are known. The headstamp is “DOMINION 45 AUTO.” The cases do not have cannelures. Primer cups are brass on all that I have seen. Some of a red primer seal and some are without it.
No military .45 ammunition was made by Canada during the Korean War, or at least none has ever surfaced. However, in 1967, Dominion did make a special run. I have no information who it was for, or why it was made. The headstamp was “+ DA 62” (the ±mark I have used to signify the normal “cross in cricle” NATO mark, which I can’t reproduce here). These round have no case cannelures, brass primer cups, and black primer seal. It is thought that a bunter for 7.62 NATO was used for the headstamp. There are rounds obviously contemporary to those with “67” date, also from Dominion Arsenal and with the same characteristics, with no headstamp.
All of the Canadian .45 ammunition, military and commercial, used a GM FMJ RN bullet.
I hope this is of some assistance.
Reference: John Moss notes
"British Service Pistol Calibre Ammunition," by Labbett & Mead,
Technical Ammunition guide Series 2, Pamphlet 3, page 25.