This bottlenecked, centerfire rifle ammunition, adopted by the British Army in 1871, combined a .450 inch diameter bullet with a unique case design resulting in a .577 inch diameter at its base. Black powder propelled a hardened lead bullet at approximately 1,350 feet per second. This distinctive round remained in service for three decades, seeing action in numerous colonial conflicts.
Representing a significant advancement in military firearms technology, the round offered increased range and accuracy compared to its predecessors. Its adoption coincided with the transition to breech-loading rifles, marking a turning point in battlefield tactics. Though later superseded by smaller caliber, smokeless powder cartridges, it holds a prominent place in military history, symbolic of British imperial power during the late Victorian era.