Certainly unusual. What strikes me is that they followed the RN protocol of marking rifles "N" not "RN" as one would expect, for in those days it was of course the RCN, not the CN it later became under Turdeau's little unification adventure fortunately later reversed in name at least under a Conservative government.
The other little oddity is that having stamped the serial number horizontally on the magazine, as I believe the RN did on the rifle body to allow easier reading in the vertical racks of a ship's armoury, they put the SN on the forend vertically suggesting along with the standard marking of the rifle bodies that these came from Army rather than RN stocks; perhaps even from stocks in Canada? We did have a very large navy at that time.