In 1916, the Canadian Expeditionary Force was desperately short of light machine guns. Since the Ross rifle had finally been taken out of service, there were large numbers of surplus rifles. That year, Joseph Huot, an engineer from Richmond, Quebec, adapted the Ross' straight-pull bolt action. His sample model, which shared 33 parts with the Ross Mark III, had a gas piston parallel to the barrel, which moved a sleeve on the bolt backward, operating the action. To absorb excess energy, the bolt was buffered. The entire mechanism was sheathed in sheet metal. Huot copied the cooling system from the Lewis Gun, then standard in British Army service. It fed from a 25-round drum magazine. He filed Canadian patents; #193724 on 8 March 1917 (granted 4 November 1919) and #193725 on 13 November 1917.