Artillery Park, Ville de Québec, Canada

I copied the following from a tourism website:
A cartridge factory was established in 1879 to manufacture ammunition for the Canadian Army, an activity that continued until the factory was closed in 1964.
How did the headstamps look?

The industrial life of the area began in 1879, when the Canadian government converted the barracks, which had been abandoned since the departure of the British troops in 1871, into a cartridge factory to manufacture ammunition for the Canadian Army. The factory was located in the New Barracks and the Dauphine Redoubt served as the residence of the superintendent.

In 1901, the cartridge factory experienced large-scale growth and the name was changed to the Dominion Arsenal. Two years later, an iron foundry was erected in the gorge of the St. John bastion and in 1908, the old parade ground disappeared under a huge workshop.

During both World Wars, the Dominion Arsenal played a predominant role in Canada’s war efforts. Several thousand men and women of Quebec worked there. In 1945, the Arsenal became part of Canadian Arsenals Limited, a Crown corporation. The factories of Artillery Park slid into decline as the production of ammunition shifted to other workshops of the conglomerate. They were closed permanently in 1964.

Dominion Arsenal used DAC headstamp and the DA headstamps.

The Dominion Cartridge Factory started head stamping with the commencement of .303" production in the late 1890s with D^C hs.
Previous production of coiled case .577" Snider and .450 MH had no hs.

Dominion did use DC headstamps at their main plant early as stated. DAC was also used at their other subsidiary plants from the early 1900’s up to 1950’s. Samples such as:

Where were the subsidiary plants of Dominion Arsenal which made small arms ammo?
The DC16 HS is from Dominion Cartridge Co a totally separate private company.

Dominion Cartridge Company was entrusted to Manage and run the Dominion Arsenal Operations as they were the only ones in Canada with large scale cartridge manufacturing knowledge. Dominion Cartridge Company did make ammunition both under their name and under the Dominion Arsenal banner (mainly war time contracts) as they were largely one and the same. It is confusing due to the same names and the fact that Dominion Cartridge company, Montreal, did run the Federal government arsenals. Dominion Cartridge Company also ran and managed Defence Industries with the DI headstamp who operated in Brownsburg and in Verdun,Quebec during WW2 and Trois Rivieres Munitions Plant (TR headstamp), Trois Rivieres, Quebec. The difference being that the government arsenals were fully 100% funded by the Canadian government so this was quite the deal for the DC Co. Dominion Arsenal itself had several factories manufacturing components. The two most notable cartridge Factories for Dominion Arsenal were in Lindsay Ontario and in Valcartier, Quebec (Just north or Quebec city and often referred to as just Quebec).