Why the infamous Dum-Dum bullet was banned from war but remains a police staple.

Countries & Cities · Published 3 October 2026 Swipe more like this →

In short: Designed to mushroom upon impact, expanding bullets maximize stopping power by transferring kinetic energy and preventing over-penetration. While these traits make them ideal for hunting and law enforcement, they were outlawed in international warfare over a century ago. The history of this projectile reveals a complex debate over military necessity.

The term 'Dum-Dum' originated at the Dum Dum Arsenal near Calcutta, India, where Captain Neville Bertie-Clay developed expanding rounds for the .303 British cartridge in 1896. These bullets were designed to solve a tactical problem: small-caliber, full-metal-jacketed rounds often failed to stop charging adversaries, who could continue advancing despite being wounded. By removing the jacket from the nose, the British created soft-point bullets that expanded upon impact, creating larger wound channels and increasing stopping power.

The international community reacted swiftly to these developments. In 1898, the German government protested the use of the Mark IV bullet, arguing that the wounds it produced were inhumane. During the 1899 Hague Convention, British representative Sir John Ardagh famously defended the ammunition, contrasting the 'civilized soldier' who accepts a wound with the 'fanatical barbarian' who requires a more immediate physical stop. Despite these arguments, the delegates voted 22–2 to prohibit the use of expanding bullets in international warfare.

This prohibition, codified in Declaration III of the 1899 Hague Convention, significantly predates the Geneva Conventions. While the ban was initially limited to conflicts between signatory powers, the International Committee of the Red Cross now considers it customary international law. However, the United States maintains that expanding bullets remain legal under conditions of clear military necessity. Furthermore, the 2010 Review Conference of the Rome Statute in Kampala classified their use in non-international armed conflicts as a war crime.

Outside of war, the use of expanding ammunition remains widespread and legal. Law enforcement agencies utilize them because they are less likely to pass through a target, thereby reducing the risk of accidental injury to bystanders. Similarly, hunters rely on the mushrooming effect to ensure a quick, humane kill. Whether through hollow-point or soft-point designs, the core mechanism remains the same: controlling the bullet's expansion to balance penetration with the transfer of energy.

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