The Ordnance BL 15lber (also given the suffix 7 cwt) was a British Field Gun, and the standard Field Artillery piece during the Second Boer War of 1899 to 1902. The Ordnance 15lber was a modified version of the older Ordnance 12lber 7 cwt, which was modified to accept the larger 15lb shell.
The Ordnance 15lber was virtually identical to its predecessor, the Ordnance 12lber 7 cwt. The modification was designed around the beginning of the use of cordite in shells. The 12lber 7 cwt was cited as being difficult to use/maintain, particularly when it was required to be moved around the field quickly, as it was heavy whilst not firing a particularly powerful shell. It was therefore deemed that the 12lber 7 cwt would be better off firing the new larger 14lb shell introduced with the use of cordite.
The Ordnance 15lber would also end up being fitted with a primitive anti-recoil device, a practice which had commenced from 1899 with the majority of British made Artillery. This device involved a spade which would be forced into the ground with the recoil of the shot. This mechanism involved a wire attached to steel cylinder mounted on the trail.
The major changes in the Ordnance 15lber's design came in the evolution of it's carriage. Various attempts were made to reduce recoil, involving a system of drag shoes (which were placed behind the wheels to prevent the gun from jumping backwards (from the force of the recoil) and chained to various parts of the carriage) and on the Mk II edition of carriages a hydraulic buffer was fitted (albeit not successfully) to reduce recoil and improve rate of fire.
The Ordnance 15lber was identical to its predecessor in terms of caliber, with the ability to fire a shell measuring 3in in diameter. However the Ordnance 15lber was capable of firing any shell below 15lb in weight, firing a 14lb cordite shrapnel shell.
The Ordnance 15lber would become the standard Field Artillery piece during the Second Boer War (although other Field Guns would also be used). Its use would be resticted by the introduction of the QF 18lber after the Boer War, however, although the Ordnance 15lber would continue to serve through the First World War in the East Africa Campaign. A total of 349 Ordnance 15lbers would be used during the Boer War, with 4 of these examples being shipped to the East African front during the First World War.
The excessive weight of the Ordnance 15lber meant that it required 6 horses, grouped in three pairs, to tow the pieces in the battle field.