The DCRA did not purchase rifles for sale to members as I understand it.
From the available documents we know that individual members of the Provincial Rifle Associations were able to purchase Enfield .303 and .22 rifles directly from the CanadianMilitary.
Many if not most of these rifles would have been Long Branch manufactured, although many Savage and Britishmanufactured No4MkI rifles with Canadian property markings exist.
The .303 No4 rifles converted to 7.62 NATO (commonly called DCRA rifles) were sent by their owners thru the DCRA to CAL to be converted to 7.62 NATO - these rifles are composed of every manufacturer and model which existed in c.1964 (No4MkI, No4MkI*, No4MkI/2, No4MkI/3 and No4Mk2 rifles).
It is recorded that if the supplied action failed inspection, the receiver and/or bolt body was replaced with an un-numbered Long Branch No4MkI* action from stores (mostly dated 1945 & 1955-56)- this is one reason so many "DCRA" 7.62 Long Branch actions show British/Savage or out of sequence by date serial numbers - and no sign of removal of a previous number.
I have owned several "DCRA" 7.62 rifles which were built on No4MkI/3 LB and Savage receivers (all converted to MkI/3 status in the UK, for the UK military) and quite a number built on mid 1950's British No4Mk2 actions.
Fulton's, Parker-Hale and several other British retailers were happy to sell by mail order to Canadian riflemen, many of whom travelled to the UK annually to compete in the matches.