They had both calibres in service, several thousand. Before that were Enfield MkIIs in .476. NWMP, then RNWMP, then RCMP markings on handguns. Some just marked MP. They were well armed for the day.
The two calibers of 455 and 45 Colt posed an interesting dilemma for them.
1904 'Royal' was bestowed upon the NWMP and they became the RNWMP. The Colt New Service was 1st ordered, and they were chambered in .455 Eley & re-ordered 3 more times thru 1914.
1918 they switched to the .45 Colt chambered NS. This is the period that 724 S&W "455 Mk II Hand Ejector - 2nd Models" chambered in 45 Colt were ordered by the RNWMP. No serial # list known, all produced by Feb 1916, Pg. 203 H of S&W.
1920 RNWMP merged w/the Dominion Police Force to become a Canadian wide force, the Royal Canadian Mounted Police (RCMP).
1920 thru 1942 45 Colt NS revolvers were re-ordered exclusively except for 1932 when the last batch of 455 Eleys was ordered. To solve the issue of two different cartridges, all 45 Colt chambered guns were moved to eastern Canada and all 455 Eleys to west of Thunder Bay in Northwest Ontario.
1954 all .45 caliber revolvers were retired and the S&W .38 Spl Military and Police (Pre mod 10) was adopted (thought to be 5 ½" barrels).
1964 retired .45 caliber revolvers were first offered to Force members for $12 ea. Then the remainder were sold to the general public.
Revolvers were usually stamped with variations of the RCMP letters. Of the 3,195 Colt NS revolvers, only 2800 were actually stamped with an issue number.
Yes they were well armed, for a long period they used Model 1876 lever action rifles chambered in .45-75.