Does the top of the barrel have the "CA" cartouch of Canadian Arsenals Limited (CAL)?
Does the barrel have bayonet lugs?
DCRA rifles of both 7.62 and .303 are commonly found marked "Regulated by Fultons" or "AGParker" or "Parker-Hale" ect.
It seems that Commonwealth target shooters availed themselves of the sevices of the various famous UKgunsmiths during competitions (Bisley ect.) in the UK.
There are a raft of Canadian/Australian& NZ gunsmiths who also did a booming business.
I have a .303 DCRA target rifle at some point "Regulated by Fulton's" and "Targeted by Gibault" here in Canada...