One method of lightening the bullets used was to provide a deep cavity in the nose of the bullet. Express rifles used larger powder charges and lighter bullets than typical for the time to achieve very high velocities for black powder cartridges. The earliest examples of bullets specifically designed to expand on impact were those fired by express rifles, which were developed in the mid-19th century.

In this case expansion was a side effect of materials, and there is no evidence that the bullets were designed to expand upon impact. The adoption of rifling allowed the use of longer, heavier bullets, but these were still typically constructed of soft lead and would often double in diameter upon impact. These would often flatten upon impact with the target, causing a wound larger than the original diameter of the ball. 458 hunting round (next to a Ugandan 500-shilling coin for size reference), after killing an African buffaloД®arly bullets were typically made in the form of spheres of nearly-pure lead, which is a soft metal. The expansion itself is sometimes called mushrooming.ДЄnother early name was General Tweedie's 'mushroom bullet', cited in the New York Times in 1892. Manufacturers have many terms to describe the particular construction of the various types of expanding bullets, though most fall into the category of soft-point or hollow-point designs. 303 designs is considered slang by most ammunition and ballistics sources.

The use of the term 'Dum-dum' applied to expanding bullets other than the early. These were not the first expanding bullets, however hollow-point expanding bullets were commonly used for hunting thin-skinned game in express rifles as early as the mid-1870s. 303 British cartridge, including soft-point and hollow-point designs. There were several expanding bullets produced by this arsenal for the. Such a bullet would have less possibility of penetrating body armour or heavy equipment worn on the body.Д¬omposite image of the British Medical Journal article describing Capt Bertie-Clay's new type of bullet (British Medical Journal 1896 2:1810)Д®xpanding bullets were given the name Dum-dum, or dumdum, after an early British example produced in the Dum Dum Arsenal, near Calcutta, India by Captain Neville Bertie-Clay. to penetrate a windshield or heavy clothing. Even then, some penetration is needed, e.g. For this reason, and to maximize the stopping effect, law enforcement organizations use expanding bullets.

This reduces the risk of accidental injury to bystanders. Д®xpanding bullets are less likely to pass through the target, and if they do, they will exit at a lower velocity. The velocities at which the bullets hit affect their expansion and penetration. Bullets used for medium and large game need better penetration, which means bullets designed to maintain integrity and for less expansion. There are a number of designs used for hunting different game and for use in weapons with different muzzle velocities. For this reason expanding bullets are often used in hunting because their stopping power increases the chance of a quick kill. This will slow the bullet down and more of its kinetic energy will be transferred to the target, creating a larger wound channel. Expanding bullets are designed to expand on impact, sometimes as much as twice the diameter.

Dum-e