I surmise that you have one of those three-inch barelled items. I recommend 140 grain loads for the best balance between velocity, bullet weight, and gun durability.
I don't believe that anyone has documented these as being used by RCMP. It is more likely they were from the Canadian military police, or some local force, although most seem to agree that they came here from the great socialist nation to the north.
If recoil is a problem, you can use Plus P .38 rounds, and I suggest Speer's new 135-grain item, or the old lead FBI load.
Lone Star