The Ordnance QF 3 pounder 2 cwt gun was a 47 mm British tank gun based on the Ordnance QF 3 pounder Vickers naval gun, mounted on Vickers-built tanks in the 1920s and 1930s. The gun was produced in 31 calibre (59 inch) and 40 calibre (74 inch) versions. The weapon only fired a solid shot, and was stated in the requirements of the A6 series of Vickers Medium tanks to have the ability to penetrate the armour of contemporary hostile tanks at a range of 1000 yards. The Vickers Medium Mark I was equipped with the Ordnance Quick Firing 2cwt Mark I version of the weapon, whilst from the Vickers Medium Mark II the Mark II version of the 3-pounder was utilized.