Webley .455 Ammunition

Good Evening Gentlemen......

Stopped at a garage sale on the way home from work tonight and found the following.....

An un-opened box of .455 revolver ammo.....

Would love to find out what the markings mean, am only gessing that they were made or packaged December 19th, 1930....

And I know of course that the C Broad Arrow signifies Canadian Govt. Issue.....

Military????? R.C.M.P.??????

Mike