5 Shot Mags For Enfields
The Enfield is exempt because it isn't a center fire semi-automatic. You can have a 20 round mag in a Mauser if it is specifically designed for it. The only exception to the 5 shot rule that I know of is the M1 Garand, it is specifically mentioned in the laws. There are some exceptions to the mag rule if the magazine is considered rare or of historically significance.
Does any province limit the amount of rounds for hunting? I know the Migratory game laws only allow three rounds for waterfall.