The BL 7.2-inch howitzer was a heavy artillery piece used by the British Army throughout the Second World War. History In 1940 the British Army concluded that the only heavy howitzer available to it, the First World War-era BL 8-inch howitzer, had insufficient range for the conditions of the Second World War. As a stopgap the decision was made to re-line the existing barrels to a smaller calibre and develop a new range of ammunition to achieve the desired ranges. Marks I–IV The 8-inch barrels were re-lined to and the old carriages were retained although the original steel rimmed wheels were replaced with new pneumatic balloon-tyre wheels, as was consistent with the motorisation of the British Army. The new four-charge ammunition increased the range to , but when fired at full charge the recoil caused the weapon to rear violently and jump backwards. To help counter this, two wedge shaped ramps were placed behind the wheels although the gun could sometimes still jump over them, presenting a hazard to crews. Marks I–IV differed only in the original 8-inch barrel used and the type of conversion; some barrels and carriages were also supplied from US First World War stocks. Mark V In 1944 several 7.2-inch barrels were placed in the US Carriage M1 used by the 155 mm Long Tom already in use by the British Army, becoming the BL 7.2-inch howitzer Mk V. Few Mk Vs were produced and it was never issued to batteries, as it was apparent that the Carriage M1 was capable of accepting greater recoil forces. Mark 6 The BL 7.2-inch howitzer Mk 6 (there was a shift from Roman numerals) retained the Carriage M1 of the Mk V but had a new built 7.2-inch longer barrel than previous marks, additionally a fifth charge was added to the ammunition. The longer barrel and extra charge provided an increase in range to , and the new carriage also provided a far more stable platform, greatly increasing accuracy. The Mk 6 was considered a highly effective gun and it was retained in service after the war. Use The original marks performed well. The first 7.2-inch howitzers were issued to batteries from mid-1942 and used in action in North Africa and later following the Normandy landings. In Burma they were provided as a pool of two guns per corps and used by Regiments as required. By the end of