Ordnance QF 18-pounder Field Gun, Royal Artillery Park, Halifax, Nova Scotia. The Quick Firing 18-pounder Field Gun had a maximum range of 5,670 metres and a firing rate that could reach 20 rounds a minute with the use of cartridge ammunition. This gun also included an aiming device that permitted indirect fire. The Ordnance QF 18-pounder Field Gun, or simply 18-pounder Field Gun, was the standard Field Gun used by Canadians in the First World War era.