Members of the Canadian Motor Machine Gun Brigade clean and repair an assortment of machine-guns: a captured Maxim MG-08 (centre); Vickers Mk 1 (left); Lewis Mk 2 aircraft machine-gun (right). Machine-gun crews were equipped with a cleaning kit, tool kit, and spare parts wallet for each machine-gun that they were issued, and it was the crew that was responsible for minor repairs to worn or broken parts and the daily cleaning of the gun. Despite this cleaning and repair, the average lifespan of a water-cooled barrel in a Vickers machine-gun was between 15,000 and 20,000 rounds. If more rounds were fired than this, the gun would steadily loose accuracy and effectiveness.
George Metcalf Archival Collection