The first handguns issued by the North West Mounted Police (which would later become the modern RCMP) were 330 Adams revolvers, requisitioned by the new police service in March 1874, and shipped over from England. Upon their receipt in July of that year, the Mounties were dismayed to find thoroughly worn out Adams Mk I 5-shot conversions from old percussion revolvers. These were found totally unfit for frontier service, and an appeal was sent back to England for something better.

A replacement shipment arrived in October 1875, and this time they received 326 much better Adams MkIII revolvers (330 were shipped, but 4 were stolen in transit). The MkIII pattern was a purpose-made .450 Adams cartridge revolver, holding six shots with a double action trigger and solid frame. These served very well, and the. NWMP ordered more in 1880 - for which they instead received Enfield revolvers, which had replaced the Adams in British military service by that time.

The 326 Adams MkIII revolvers issued by the NWMP were marked by a local gunsmith upon their arrival. The right side of the frames are marked “C M.P.” (presumably Canada Mounted Police) and given a police inventory number just below the barrel (in addition to the serial number above the trigger). These issue numbers were defaced when the guns were sold out of service.